This PDF file contains the front matter associated with SPIE Proceedings Volume 12062, including the Title Page, Copyright information, and Table of Contents.

Based on cascaded Mach-Zehnder lattice filter, an eight-channel silicon photonic (de-)multiplexer with flat passband is demonstrated in the O-band. The insertion loss of the device is -0.55~-2.48dB and the channel crosstalk is below -7dB. The FSR and channel spacing are about 36nm and 4.4nm respectively.

We propose and theoretically analyze a DFB semiconductor laser monolithically integrated with anti-symmetric Bragg grating (ASBG) modulator. A π phase shifted Bragg grating with single-mode ridge waveguide and an ASBG with multimode waveguide supporting the fundamental transverse electric (TE₀) mode and the first order transverse electric (TE₁) mode, are joined by a tapered waveguide. After adding a phase shift section between the taper and ASBG, the electro-optical (E/O) response of ASBG modulator increases by 37.9% compared to the normal Bragg grating modulator (BGM), and becomes sensitive to the effective refractive index change of the straight waveguide. The proposed integrated device can be applied in sensing.

The polarization noise is the major factor affecting the long-term zero-bias stability of the integrated optical gyroscope (RIOG). Compared to the silicon, the Si₃N₄ waveguide has excellent polarization-dependent loss and can maintain a single polarization state. In our work, a transmissive Si₃N₄ WRR with a bending radius of 8 mm is successfully designed and fabricated. We prove its single-polarization performance through experiments at different temperature. The successful design and fabrication of this WRR is expected to achieve high precision RIOG.

Plasmonic devices are considered as a potential platform to realize highly integrated photonic circuits. Optical logic gates are fundamental computing and light-controlling elements in optical circuits and optical computing, and many plasmonic logic gates have been studied. However, these devices can only realize single or several specific logical operations. In this work, we propose a multiport plasmonic system to realize all-logical processing based on coding metamaterials (CMs) and inverse design. We utilize nondominated sorting genetic algorithm-II to optimize the distributions of CMs. After optimization, the simulation results exhibit that all types of logic gates (AND, OR, NOT, NAND, NOR, XOR and XNOR) can be obtained with the operating wavelength of 1.31μm and a small footprint (0.8×1.1 μm²). Moreover, the extinction ratio between logical "1" and "0" states exceeds 20 dB for OR, NOT, XNOR and XOR logic gates.

Optical displacement detection is widely used in various MEMS sensors because of its high sensitivity. The optical accelerometer has a high theoretical resolution. To increase the measurement range, we proposed a high-resolution micro-optical accelerometer with electromagnetic force feedback. The optical principle, mechanical structure, and manufacturing process are analyzed. The accelerometer is predicted to work in the first modal with displacement sensitivity at 605 nm/g, corresponding to 0th diffraction beam optical sensitivity 1.1 %/nm. The designed electromagnetic driver can increase the acceleration measurement range from 0.066 g to ±20 g. These results provide a theoretical basis for the design and fabrication of a high-resolution micro-optical accelerometer with an electromagnetic driver.

Silicon photonics is becoming the leading technology in photonics for a variety of new applications. However, due to the large volume and high cost of traditional optical devices, they are not suitable for high integration. It is challenging to further improve the integration and performance of silicon photonics. Here, we proposed a power splitter designed by inverse design algorithm has high transmission efficiency and compact structure size, which is helpful to the integration of photonic integrated circuit (PIC). The emergence of inverse design algorithm makes a great breakthrough in the problems existing in optical devices. In recent years, inverse design algorithms have attracted researchers' attention because of their ability to regulate light transmission by changing the refractive index distribution in the subwavelength structure. Direct-binary-search (DBS) algorithm, as the most commonly used inverse design algorithm, is applied to the design of on-chip photonic devices because of its simple working principle and high optimization efficiency. As one of the important components of photonic integrated circuits, on-chip power splitter plays an important role in optical communication system. Power splitters which can achieve any power ratio are widely used in optical interconnect devices. The traditional arbitrary power splitter can achieve different split ratios through different structures, but they can not achieve controllable split ratios in the same device, which is an obstacle to the integration of PIC. Phase change materials have been widely used in controllable photonic devices due to their unique optical properties. We combined the DBS algorithm to program and control the Ge₂Sb₂Se₄Te₁ (GSST), divided the whole device into multiple units, and optimized the design of each unit. Finally, the phase distribution in line with the target splitting ratio was obtained, and the high-efficiency and small-size power distributor was realized. A 3D finite-difference time-domain (FDTD) solution was used to simulate the device, and the TE₀ mode light from the input waveguide was transmitted through the coupling region to the upper and lower output waveguides. Simulation results show that the device size is only 2.4 × 2.4 um², and in the wavelength range of 1530 nm-1560 nm, the power split ratio of 1:1.5 and 1:2.5 is achieved. This method is helpful for the development of programmable integrated photonic interconnect devices.

Based on the principle of one-dimensional photonic crystal, ZnS and SiO2 were used as the main substrates to study the surface optical modification of various flexible fabric substrates. One dimensional photonic crystal coating structure system was constructed by extending the photonic band gap by multi heterojunction superposition and introducing disorder reasonably. Multilayer coating was carried out on the fabric surface by vacuum evaporation technology to realize the infrared selective spectrum regulation on the fabric surface. The surface spectral emissivity and coating adhesion of the fabric before and after coating were tested. The results show that the one-dimensional infrared photonic crystal structure based on flexible substrate can achieve the infrared radiation properties of infrared medium wave emissivity ≤ 0.3 and long wave emissivity ≥ 0.8; Based on this architecture, the infrared spectrum selectivity of flexible fabric surface can be realized by vacuum evaporation; For the surface of pure fabric, the bonding strength between the coating and the fabric surface is related to the surface density and surface smoothness of the fabric; Using adhesive layer to improve the surface smoothness of fabric, and further coating on this basis can effectively improve the adhesion of coating, and the adhesion level can be increased from grade 5 to grade 0; The results show that the medium wave incidence, long wave emissivity and emissivity difference are 0.15, 0.87 and 0.72, respectively; At the same time, the coating is stable in the range of 25 ℃ to 350 ℃ and has good thermal stability.

Based on Mg/Na (NO₃) ₂ and Mg/Sr (NO3) 2, the combustion and radiation characteristics of pyrotechnics in vacuum were studied. The burning rate and visible light radiation characteristics of different samples were obtained, and the relationship between combustion performance (visible light intensity and burning rate) of the sample and vacuum environment pressure were further obtained. The results show that: 1) the linear burning rate and mass burning rate of the two formulations decrease with the decrease of pressure, and the burning rate has an exponential relationship with the pressure, and the sensitivity of Mg/Sr (NO₃) ₂ to ambient pressure is slightly higher than that of Mg/Na (NO₃) ₂; 2) Under the same vacuum pressure, the visible radiation intensity of Mg/Sr (NO₃) ₂ is significantly higher than that of Mg/Na (NO₃) ₂; 3) With the decrease of vacuum pressure, the visible light radiation intensity of the two formulations of pyrotechnic composition decreased. 4) According to the test data, the light intensity pressure index of Mg / Na (NO₃) ₂ is 1.07, which is more sensitive to environmental pressure than that of Mg/Sr (NO₃) ₂ system 0.598; 5) Based on the fitting formula, it is estimated that the visible light radiation intensity of Mg/Na (NO₃) ₂ system is 16cd, which is much less than that of Mg/Sr (NO₃) ₂ system 443cd.

For the problem of indoor visible light communication fairness, a constrained least squares method is proposed to generate a uniform power distribution by optimizing the beam angle and power weight of the light-emitting diodes sources. The improved Fibonacci uniform allocation procedure is employed to determine the position of the sources. The initial power of the sources is constant, and the average value of the received optical power is taken as the target power matrix of the least squares method. The element range of the power distribution weight matrix is set according to the limit of the actual light source power adjustment, and the power of the light source is redistributed to improve the signal uniformity in the receiving surface. The simulation results show that the proposed method can improve the uniformity of the received power and the signal-noise ratio in the room. And the relative standard deviation (RSD) between the received and target power is less than 0.1. When the number of the light sources is constant, the semi-angle at the half power of the sources is optimized so that the RSD value is minimum.

A refractive index sensor is a device that can convert small changes of the refractive index into an optical signal, which usually acts as a label-free sensing technology in the field of biomedicine. The traditional optical sensor, based on refractive index sensor, could realize sensing through the interaction of light and biochemical substance on the superstructure surface. The traditional refractive index sensors are usually composed of noble metals material, and the sensing is realized by exciting surface plasmons. However, due to the ohmic loss of the metal, the quality factor and the value of the FOM of the refractive index sensor based on the metal structure are low, generally, which greatly limits the development of refractive index sensors. In this paper, the magnetic resonance refractive index sensor based on the asymmetric all dielectric cross-shaped split ring is proposed which could achieve high sensitivity and high quality factor, by inducing the metal ohmic loss and enhancing the magnetic resonance. The cross-shaped split ring metamaterial structure is applied to wireless passive sensing and is simulated by the finite element method. Simulating the interation between the incident light TE wave and the meta-surface structure produces sharp magnetic resonance peaks. We can monitor the change in the concentration of the solution around the sensor through the moving of magnetic resonance peak. For this sensor, the resonance peak wavelength is between 8680nm-8800nm in the mid-infrared, the sensitivity is 500nm/RIU, and the FOM is 909.

The pixel array of BSI CMOS image sensor is a kind of photoelectric device to obtain 2D image information. The image quality was evaluated by the modulation transfer function (MTF) of BSI CMOS image sensor pixel at Nyquist frequency. With the decreasing pixel size of BSI CMOS image sensor and the increasing spatial resolution, it is more and more difficult to improve the MTF at Nyquist frequency. According to the theoretical analysis, MTF is composed of aperture MTF and diffusion MTF, the comprehensive MTF function is usually obtained by the multiplication relationship between the two MTFs in the frequency domain. Aperture MTF and diffusion MTF have different influence factors and calculation functions, but they are related to the size of the opening. The opening here represents the sensitivity aperture and photo-sense region respectively. The smaller the opening of the detector pixel, the larger MTF will be. In this paper, the theoretical mechanism of MTF function is analyzed in detail, and the calculation results of MTF of BSI CMOS image sensor pixel under 8 typical optical wavelengths in 300nm-1000nm spectral band are listed.

An investigation on hybrid graphene-metal structure patch antenna has been carried out in the presented paper. The microwave radiation performance of the antenna is controlled by the optical tuning characteristic of graphene. The surface conductivity of graphene is changed, when variation of chemical potential is happened which can be regulated by an exterior light field. With simulations, the S11 coefficient of antenna is changed with a maximum of 32.2 dB when the chemical potential of graphene varies from 0 eV to 1 eV. The effect of different structure parameters, such as metal radiating patch sizes and graphene film widths, on the S11 coefficient in the graphene based antenna is further analyzed by simulations. With experiments, the measured S11 coefficient decreases gradually with optical intensity increases when using communication light with the wavelength of 1550 nm as modulation light. When the optical intensity of the communication light varieties from 0 mW to 25 mW, the S11 coefficient of the microwave is changed from -18.7 dB to -19 dB and the modulation depth is 0.3 dB. The results demonstrate the proposed method is a good candidate for modulating microwave directly by communication light.

In this paper, we studied the ultrafast response of the dielectric properties of monolayer phosphorene to femtosecond laser pulses by employing time-dependent density functional theory. The simulation results showed that the dielectric function of monolayer phosphorene exhibited a negative divergence of its real part at low frequency and a remarkable “quasi-exciton” absorption peak of its imaginary part after femtosecond laser irradiating. It was inferred that this type of response was induced by electron-hole pairs excited by the femtosecond laser. The nonlinear response of excited current by femtosecond laser in monolayer phosphorene was also investigated. The plasma oscillation and breakdown in monolayer phosphorene was revealed. Moreover, we showed how the degrees of freedom (intensity and wavelength) of the laser pulse could be helpful for the manipulation of the system transient response.

In this paper, we focus on a study of the response time of a liquid lens actuated by a dielectric elastomer (DE). This paper aims to determine the optimal input voltage function for obtaining a liquid lens actuated by DE with high response speed. First, we fabricate a liquid lens actuated by DE sandwiched between transparent conductive liquids. The liquid lens consists of two supporting frames, transparent conductive liquid, two passive membranes, one DE membrane, and copper foils. When a driving voltage is applied to the copper foils, the shape of the DE membrane changes, which in turn makes the shapes of the two passive membranes altered, then the focal length of the liquid lens is tuned. Second, four different input voltage functions, which including square, ramp, sine, and exponential voltages, are generated by a function generator. The power of the input voltage is amplified by a power amplifier and the amplitude is amplified by a high voltage converter. The amplified input voltage is applied to the copper foils to drive the liquid lens. Last, the time-domain response curves of the liquid lens are obtained by a photodetector. The response times of the liquid lens actuated by DE, including the rise and fall times, are obtained from the time-domain response curves. The experimental results show that the response times are different although the four input voltage functions have the same amplitude and frequency. The study shows potential optical imaging applications that require fast response speed.

As the core unit in the communication field and microwave technology, electro-optical modulators should have large modulation bandwidth and high modulation efficiency in order to meet the needs of ultra-wideband, large dynamic microwave optical transmission、microwave photonic signal processing applications、high performance and so on. In this paper, the structure of the silicon-organic composite Mach-Zehnder modulator is designed and simulated, and electro-optic organic polymers are filled in the slot waveguide, which gives full play to the large-scale integration of silicon and the advantages of organic polymer materials with high electro-optic coefficients. We obtained the data: the transmission loss was 2.2322dB/mm through the design and simulation optimization of the slot waveguide structure. At the same time, we optimized to obtain the coupling of the Strip-to-Slot mode converter for the multimode interference (MMI) waveguide mode conversion structure. The coupling efficiency was 0.9324. It can improve the modulation efficiency of electro-optic modulators, which has certain reference significance for the design of electro-optic modulators.

Broadband light absorbers are attractive for their applications in photodetection and thermal detectors. Metal-black coatings have been experimentally proven to have broadband light absorption characteristic. A large area and broadband gold-black coating was fabricated by a low-cost but effective sputtering process. The gold-black films exhibited reduced reflection of 4.81%, 2.48% and 1.93% for sputtering pressure of 50, 65 and 80 Pa in 300-800 nm spectral range, and their size reached 4- inches. A three-dimensional nanocone-like array model was proposed for the gold-black films. Then, the nanocone array of this model was embedded with many gold nanoparticles due to the rough surface of the gold-black films. The results indicated this proposed model of nanocone-like array embedded with nanoparticles can be a good tool to design broadband gold-black absorbers.

In this letter, we report a high-power all-fiber mid-infrared (MIR) supercontinuum (SC) laser source based on a short piece of centimeter level germania-core fiber (GCF). The pump source at the wavelength of 2 μm was directly generated from a single-mode fiber laser. The all-fiber seed oscillator was passively mode-locked by a SESAM to generate pulse duration of 62 ps at a fundamental repetition rate of 44.31 MHz in a linear cavity. After all-fiber thulium-doped fiber amplifier (TDFA), we obtained a high-power pump source with a spectral coverage of 1.9~2.2 μm. We only use 12 cm long 94 mol. % GCF for spectral broadening pumped by TDFA. In addition, we measured the spectral broadening after 12 cm GCF in different length of dispersion compensation fibers (DCF) corresponding to different pulse width and peak power. As a result, we obtained a broadband SC source based on 12 cm 94 mol. % GCF extending from 1630 to 3205 nm and a maximum output average power of 15.07 W with a slope efficiency of 34.2%. The 20 dB spectral bandwidth was over 1000 nm spanning from 1.89 to 2.92 μm. To the best of our knowledge, this is the first demonstration of 15-W level SC laser based on germania-core fiber with long wavelength edge extending beyond 3.2μm. Further broadening of spectrum is limited to pump power.

The application of distributed Brillouin optical fiber sensing technology in dam health monitoring is mainly studied in this paper. In the dam health monitoring system, the key technology is real-time deformation monitoring. Firstly, the principle of Brillouin optical time domain analysis (BOTDA) is introduced. A long-term on-line monitoring scheme of dam strain is proposed based on the distributed Brillouin sensing technology. The scheme includes cable layout and strain test. In the test, a 200m single-mode optical cable is selected. Firstly, the center frequency shift data of the whole optical cable is measured, when the displacement load is set to 0 mm, which is used as the test reference of strain variation. Then, the 2m length of the middle part of the optical cable is stretched to perform large amplitude tensile tests and shrinkage tests. The displacement loads are 2mm, 4mm, 6mm, 8mm and 10mm respectively. Next, small amplitude tensile tests and shrinkage tests are performed. The displacement load is 0.5mm, 1mm, 1.5mm and 2mm respectively. Analysis of test data shows that, the strain measurement range of the scheme can reach ± 4500με, the resolution of the scheme can reach 20 με. The results prove that the distributed fiber Brillouin sensor system can realize the long-term on-line distributed measurement of dam strain, which meets the requirements of the dam strain monitoring. It provides an effective means for dam health monitoring and protection, and a strong support for large-scale structural health monitoring with distributed Brillouin optical fiber sensing.

Polypyrrole (PPy) is extremely suitable for fabricating piezoresistive pressure sensors owing to its good biocompatibility and excellent electrical conductivity. However, the intrinsic rigidity and brittleness of dense PPy particles are difficult to form flexible conducting elastomers which hinder its further applications in wearable health monitoring systems. Herein, we report an efficient coaxial nanofibers network strategy to fabricate 3D conductive and elastic topological film through polydopamine (PDA)-assisted homogeneous deposition of PPy particles onto PVDF nanofibers (PVDF/PDA/PPy, PPP). It is noteworthy that dense PPy particles are difficult to lonely form flexible conducting film due to its rigid conjugated-ring backbone. However, PPy particles deposit on the surface of flexible PVDF/PDA nanofiber to form 3D network conducting films, which is both conductive and elastic, with the capable of withstanding large effective strains and stresses. Benefit from their unique 3D conducting network structures with more contact sites, the obtained sensors have superb sensitivity to the subtle pressure.

Integrated optical temperature sensor nowadays has attracted extensive interests thanks to its merits of high accuracy, electromagnetic immunity, and compact size compared with the traditional solutions. So far, most of the state-of-art integrated optical temperature sensors work by spectrum detection of a resonant cavity, which has certain limitations in terms of response time and cost, and it is difficult to achieve high level integration of the overall system. To solve the above problems, in this paper we use silicon-based integrated micro-ring array technology for high-precision real-time temperature sensing. By constructing a monotonic relationship between the output light intensity of the micro-ring array with the variation of the temperature, rapid and high-precision temperature measurement could be realized. Depending on different practical scenarios, the system can be customized to adapt specific temperature measurement range and resolution. Through the optimized design, the system accuracy could be better than 60mK covering temperature range of 297K~415K, with response time better than 20μs.

In order to solve the problem of traffic congestion and unbalanced utilization of wavelength resources caused by the explosive growth of traffic demand in the next generation mobile communication network. In this paper, a multichannel all-optical wavelength converter with stable output power is designed by using germanium doped microstructure fiber. Based on the theoretical model of stimulated Raman scattering, a multi-channel all-optical wavelength converter is constructed. The waveforms of the pumped signal light and the converted detection light are analyzed, and the influence parameters of gain and flatness are discussed. The simulation results of OptiSystem show that the waveforms of the four-channel detection light and the pump signal are consistent and the output power is basically the same, and the gain fluctuation range is less than ±0.38dB, which verifies the feasibility of the method.

X-rays have the characteristics of high single photon energy, high frequency, and strong penetrating ability, are widely used in space communication, radiation imaging, medical diagnosis, non-destructive testing, and other fields. The development of X-rays has had a positive impact on broadening the use of the electromagnetic spectrum. As the core component of the X-ray application, high modulation rate, low power consumption, and excellent performance X-ray generators have been a hot research topic for decades. In this paper, a light-controlled pulsed X-ray source is modeled by simulation software. We perform simulation calculations and summary analysis on the effects of cathode structure, focus structure height, and metal anode voltage on the focal spot size, electron transit-time, and transit-time spread. At an operating voltage of 30KV, if the photocathode is 42mm in diameter, the focal spot diameter is about 1.5mm, the electron transit-time is 3.75ns, and the transit-time spread is 895ps when the focusing structure height is 6mm. And if the diameter of the photocathode is 12mm, the focal spot diameter is the smallest when the focusing pole height is 9mm, which is about 0.7mm, as for the time characteristics, the electron transit-time is 4.1ns, and the transit-time spread is 242ps. The results suggest that the light-controlled pulsed X-ray source is expected to be the next-generation source with easy modulation and short X-ray pulse properties.

The aim of this work is the formation of anti-blue light coatings which are suitable for application on 3C products. Atomic layer deposition was used to deposit Al₂O3 and TiO₂ single layer films onto glass substrates at 250 °C. Optical characterization of the films was conducted to evaluate whether the thickness was suitable for the fabrication of multipair reflective coatings. The refractive indices of the films measured at an optical wavelength of 450 nm were 1.68 (67 nm, Al₂O₃) and 2.67 (42 nm, TiO₂). Al₂O₃/TiO₂ multilayer DBRs with 1.5, 3.5, 5.5 and 7.5 pairs were deposited on glass substrates. The thickness of each layer of Al₂O₃ and TiO₂ films were 63.7 and 49.6 nm in the multilayer structure measured via FE-TEM. When 1.5-pair Al₂O₃/TiO₂ DBRs were deposited on the glass substrate, the films had high transparency, and less reflective effect were observed. As 3.5, 5.5 and 7.5-pair DBRs were deposited on the glass substrates, the Bragg reflection effect became apparent. We found 7.5-pair Al₂O₃/TiO₂ DBRs prepared by ALD had the best central and bandwidth of the Bragg reflection effect for blue light.

Since carrier dispersion and carrier absorption exist at the same time when the phase shifter is under phase modulation, decrease in extinction ratio is inevitable for silicon-based MZI modulator based plasma dispersion effect. In this paper, we demonstrate an optical modulator at 1550 nm wavelength band, using a cascaded compensation method. We balance the optical intensity in the two phase shifters of the MZI structure during modulation. With cascaded compensation method, the modulator has an extinction ratio of 51 dB and a dynamic extinction ratio of 10 dB at bitrates of 40 Gb/s.

Although microwave and light wave belong to the same electromagnetic wave, the huge difference in frequency makes them present completely different laws in generation, transmission, control, detection and interaction with matter. The research on how to use microwave and light wave as the carrier for information transmission and processing constitutes the main content of microwave technology and photon technology, which support the two basic technologies in today’s information society. Since the 1990s, these two technologies began to merge and produce a new interdisciplinary microwave photonics. It mainly studies how to use optoelectronic devices and methods to achieve microwave/millimeter wave signal generation, transmission, distribution, processing and other functions that are too complex or impossible to achieve only relying on the microwave system. In the future, a new challenge to microwave photonics is proposed: while achieving higher speed, bandwidth, processing power and dynamic range, devices and systems are required to have small size, light weight, low power consumption and stronger EMI (Electromagnetic Interference) resistance. This requirement leads to a new research direction, namely integrated microwave photonics, which aims to realize the chip integration of microwave photonic system, reduce the cost, size and power consumption of the system, increase the tunability, programmability, mechanical flexibility and electromagnetic resistance of the system, and realize the chip and product of microwave photonic system. This paper summarizes the development status of microwave photonic integration technology and silicon-based photonic devices, and points out that the silicon-based microwave photonic chip will become the key technology in the military and civil fields.

The discovery of surface-enhanced Raman scattering (SERS) can enhance the signal of molecules adsorbed on the roughened surface by a million times and o btain high-quality Raman scattering spectra. The ideal SERS substrate has high repeatability, reproducibility and uniformity, so regular hot spots are needed, and the hot spots are the areas with very high electromagnetic fields on the substrate. In this p aper, an one-dimensional grating with silicon substrate, silicon dioxide teeth and silver -plated film is designed. Under the 633nm excited light wavelength, the grating period is 520nm, the duty cycle, silver film thickness and grating tooth height are adjusted to simulate the control variables, and the reflection order spectrum and energy absorption spectrum varying with the variables are calculated. The script of finite -difference time-domain (FDTD) method is written to simulate the electric field maximum spectra of different structures. It is also analyzed that the absorption maximum region and the reflection minimum region are the key points of the maximum field strength. Finally, two rectangular groove gratings are designed as SERS substrates, which can be enhanced by an order of magnitude of 5 orders of magnitude .

As high-precision fiber optic gyroscopes, especially three-axis high-precision fiber optic gyroscopes, face harsh electromagnetic environments, Y-junctions have become a key component that affect the precision of fiber optic gyroscopes. A high extinction ratio Y-junction is fabricated to suppress the polarization mode coupling of the fiber optic gyroscope and reduce the noise of the fiber optic gyroscope. The experimental results show that the above methods effectively solve the effect of the deterioration of the precision of the fiber optic gyroscope caused by the Y-junction.

Compared with laser gyroscope, it is still difficult for the scale factor stability of high-precision fiber optic gyroscope (FOG) to achieve better than 1ppm under variable temperature conditions due to the influences of the fiber coil and the light source. We proposed to add multiple precision temperature measuring devices to the fiber coil, and established a multi-modulus temperature compensation model by measuring the temperature at multiple locations of the fiber coil. The stability of the FOG scale factor is greatly improved.

As a two-dimensional material, graphene shows excellent properties in many aspects. Among them, it exhibits extremely high carrier mobility, excellent thermal conductivity, and high temperature stability due to its unique lattice structure, so it is superior than previously used conventional materials in the field of thermal applications. This paper introduces the study of graphene heating film of centimeter scale. We transfer large areas of graphene films to four different substrates to study the characteristics of heating temperature, thermal response time and heating uniformity of graphene films. Experimental results show that graphene with a heating area of 0.7cm × 1cm can be rapidly raised from room temperature to above 100℃ at a DC voltage of 25V. According to the experimental results, graphene performs well in both heating temperature and heating rate compared to traditional heating materials, which provides good prospects for the use of graphene in fields such as deicing, defogging, medical physiotherapy and others.

In the novel application of light torques, we determined and characterized the orienting torque acting on micron-size crossing shape cylinders by the irradiance of a linearly polarized laser. The dielectric and gold materials commonly employed for the particles. The theoretical model is based on the Lorenz-Mie method, by three-dimensional (3D) finite elements analysis (using Radio Frequency Module in COMSOL) calculating the Maxwell stress tensor (MST). To understand the different mechanisms of optical manipulation, the gradient force, scattering force, total force in the x, y and z directions and the trapping potential U are also described and explained. Numerical results show that the optical torque spectrum is in accordance with shape, size and material of the particle. In doing so, we demonstrate how crossing shape cylinders outperform single cylinder and offer unprecedented opportunities to expand the control of optical force and torque at the (sub) micron-scale, as a rotating micron/nanomotor for a variety of applications in nanoscience, biophysics and engineering.

ultra-compact silicon mode (de)multiplexers are demonstrated based on asymmetric directional couplers with subwavelength structure (ADCWSS), the subwavelength structure is a series of corrugation on the sidewalls of waveguides, and the two arrays of corrugation extend into the gap region between the waveguides and interlace with each other. The coupling length of ADCWSS are 5.6μm, 6.5μm, and 7.9μm for TE0-TE1, TE0-TE2, TE0-TE3 mode (de)multiplexers, respectively. The four-mode mode-division-multiplexing (MDM) link was fabricated and measured. The insertion losses of TE0-TE0-TE0, TE0-TE1-TE0, TE0-TE2-TE0, and TE0-TE3-TE0 are 0.2dB, 0.7dB, 0.7dB and 0.9dB (around 1.55μm). The maximum insertion losses and crosstalk are 2.4dB, 2.9dB, 3.0dB, 4.0dB and -18dB, -19dB, -16dB, -18dB for the TE0, TE1, TE2 and TE3-mode channels over a 50-nm bandwidth.

Firstly, the requirements of ultra-high precision gyroscope for light source are analyzed. Ultra-high precision fiber optic gyroscope (FOG) is used in long-term inertial navigation system for naval vessels, which requires high precision, stability of scale factor and nonlinearity of scale factor. The stability of the average wavelength of the light source directly affects the stability of the scale factor of the FOG. The high power output of the light source combined with other noise reduction methods can improve the signal-to-noise ratio of the FOG, thereby improving the detection accuracy. The coherence of light source spectrum will affect the coherent noise of the FOG, the symmetry of spectrum will affect the nonlinearity of scale factor, and the spectral width will affect the noise level. Therefore, ultra-high precision FOG requires high power, high wavelength stability, large spectral width, hyperspectral symmetry and low coherence light source. Second, an ASE source for ultra-high precision FOG is proposed in this paper. In terms of optical path, the optical path structure of ASE light source and the means to improve the average wavelength stability of the light source are analyzed. Two-stage Erbium fiber structure is used to obtain high power output. Faraday rotating mirror is used to reduce the polarization-dependent gain in Erbium fibers. High stability of average wavelength is achieved by optimizing erbium fiber parameters and pump power. The non-subpeak Gauss spectrum of the coherence function is chosen as the spectral scheme. In the design of the filter, the orthogonal experiment and hardware-in-the-loop simulation are used to optimize the filter parameters and perform the whole spectrum shaping filtering. The output spectrum width is over 20 nm, which is much wider than 7-13 nm of traditional filtering method，and reduces the noise of gyro noise. In the drive circuit, the high stability temperature control of the pump is realized. By controlling the temperature characteristics of the feedback loop devices, the power stability of the light source is greatly improved by using the power feedback mode. The ASE light source designed above can provide power output of more than 30 mW. The wavelength stability is less than 5 ppm in the whole temperature range, and less than 1 ppm at the constant temperature. The power variation is less than 1%, and the spectrum width of output is more than 20 nm. It is an ideal light source for ultra-high precision fiber optic gyroscope..