This PDF file contains the front matter associated with SPIE Proceedings Volume 7053, including the Title Page, Copyright information, Table of Contents, and the Conference Committee listing.

Diffractive optical elements with application specific tailored properties can be fabricated by light induced alternation of the material's refractive index. Holographic polymers or photoresists are typically used for permanent optical structurization. Today, photostructurable media become core elements of photonic systems with innovative capabilities. We investigate different classes of organic photosensitive materials in order to optimize the interaction between the material and an optoelectronic system around. Some exemplary applications are microholographic data storage, 3D nano/micro structurization, optical patterning for advanced security features. Key issues include dynamic material response, spectral and temporal grating development, influence of the light intensity distribution, effects of pre-exposure and post-curing, etc. Materials under investigation are cationic and free radical polymerization systems, liquid crystalline polymer nanocomposites, and photoresist systems.

We have recorded 1TeraByte of data in 200 layers in the volume of one DVD-like two-photon 3D disks. Each layer contains 5GBytes of data, equal to single layer DVD capacity. The results obtained with our high-performance 1.0NA objective lens show a full disk recording of 1 TByte within a standard optical disk form factor of 120mm × 1.2mm thick utilizing our very stable and efficient materials. Very high sensitivity materials are used to store information with bit energies as low as 250pJ/bit. Materials sensitive at 405nm are been tested by recording with 405nm Nichia laser diodes. Results show that bit dimensions are further reduced enabling future recordings at 5TByte disk capacities by recording 25GBytes/layer, the equivalent of a Blu-ray disk capacity per layer.

We demonstrate a projection lithography method that induces optical index changes in a flexible polymer cable that is continuously translated through the image plane. We demonstrate that a static spot pattern generates a grid of waveguides along the cable length via a continuous extrusion process. Rotations or scaling of the optical spot array can fabricate image inverters or magnifying face plates in a single process step. The resulting polymer devices have applications in optical backplanes, endoscopes for medical applications and lightweight imaging systems.

A new approach for 4D spatial-spectral optical sensing is based on light diffraction at holographically recorded 3D refractive index gratings. At least four collimated laser beams overlapped in a photosensitive polymer layer are used to generate a periodic 3D structure. Diffraction properties are widely adjustable by varying the recording beam geometry. Different 3D photonic gratings are characterized with respect to their basic diffraction properties and the results are used in optimizing the exposure process and parameters. An optical imaging setup has been constructed to display the 4D optical filtering properties of recorded 3D gratings when illuminated by elementary intensity patterns of a white light source.

The integration of optical interconnects in printed circuit boards (PCB) is a rapidly growing field due to a continuously increasing demand for high data rates, along with a progressive miniaturization of devices and components. For high-speed data transfer, materials and integration concepts are searched for which enable high-speed short-range connections, accounting also for miniaturization, and costs. Many concepts are discussed so far for the integration of optics in PCB: the use of optical fibers, or the generation of waveguides by UV lithography, embossing, or direct laser writing. Most of the concepts require many different materials and process steps. In addition, they also need highly-sophisticated assembly steps in order to couple the optoelectronic elements to the optical waveguides. An innovative approach is presented which only makes use of only one individual inorganic-organic hybrid polymer material to fabricate optical waveguides by two-photon absorption (TPA) processes. Particularly, the waveguides can be directly integrated on pre-configured PCB by in situ positioning the optical waveguides with respect to the mounted optoelectronic components by the TPA process. Thus, no complex packaging or assembly is necessary, and the number of process steps is significantly reduced, where the process fits ideally into the PCB fabrication process. The material properties, the TPA processing of waveguides, and the integration concept will be discussed. Recent experiments employing vertical-cavity surface-emitting lasers demonstrated data rates exceeding 6 Gbit/s.

To correctly develop numerical model for any photopolymerization, understanding the initiation chemistry in both space and time is required. In photopolymer materials both the complex initiator chemistry and diffusion properties have similar timescales. To fully understand this spacial and temporal evolution we developed a number of experiments to isolate these effects. We show that for Irgacure 784 in a polymer host that the chemical reaction and diffusion are strongly coupled. We demonstrate the importance of isolating these processes.

The fabrication of 3D microstructures has been realized by numerous researchers using two-photon polymerization. The premise of these studies is that the confinement provided by localized, two-photon absorption results in polymerization only near the focal point of the focused write beam and unwanted polymerization due to superposition of the out-offocus exposures is significantly reduced, enabling the fabrication of complex structures with features below the diffraction limit. However, the low cross-section of two-photon absorbers typically requires excitation by pulsed Ti:Sapphire laser at 800 nm, resulting in polymerized features that are actually larger than those created by one-photon absorption at half the wavelength. Here we describe a single photon photolithographic technique capable of producing features not limited by the physics of diffraction by utilizing a resin which is able to be simultaneously photoinitiated using one wavelength of light and photoinhibited using a second wavelength. Appropriate overlapping of these two wavelengths produces feature sizes smaller than the diffraction limit and reduces polymerization in the out-of-focus regions while avoiding the high light intensities demanded by multi-photon initiation. Additionally, because the photoinhibiting species are non-propagating radicals which recombine when the irradiation is ceased, memory effects typical of photochromic initiators are avoided, allowing rapid and arbitrary patterning.

In order to clarify the hologram recording process for the photopolymer media, we analyzed both the creation process of multiplexed hologram and diffraction characteristics of reproduction process using a Beam Propagation Method (BPM). We also conducted experiment and evaluated the multiplexed hologram recording characteristics. By the simulation using BPM and experimental results of hologram multiplexed recording, we made clear the evaluation process of photopolymer media and recording / reproduction conditions of multiplexed holograms recording.

Photopolymers are used popularly as a recording medium for holograms. In this study, we simulate the formation of diffraction grating in photopolymers using the model based on diffusion. Moreover we analyze diffraction characteristics in detail with beam propagation method. As a result, diffraction characteristics which are difficult to analyze using coupled-wave analysis and rigorous coupled-wave analysis have been obtained. It is our expectation that the result of this analysis will provide profitable knowledge for development of holographic data storages.

We report the properties of a new polymer-guest photosensitive mixture based on two monomers with different properties as basic components. The material has been characterized by recording holographic gratings using a low power blue laser (405 nm) and a spectro-photometric technique to get the optical properties of the grating during and after recording. The detected grating shows a very high sensitivity (of the order of 10³ cm/J) and a surprising "antishrinkage" phenomenon (red-shift of the Bragg reflection grating wavelength).