Recent advances in the design of gain modules for diode-pumped solid-state lasers have allowed the manufacture of
high-powered Q-switched products. The high available pulse energy and good mode quality enable highly efficient
harmonic conversion, enabling the generation of several hundred watts of average power at a wavelength of 532nm.
Among the applications for which this class of product may be suited is the rapid drilling of small-diameter holes in
aluminum sheet. To investigate this application, plates of several aluminum alloys were drilled under a variety of
conditions. The drilled plates were sectioned and subjected to analysis by optical metallography. The initial results
indicate ways in which the process may be optimized.
Demand for higher precision, clean laser based processes has driven the development of picosecond pulse width lasers
that operate at high frequency with high average powers. Industries like microelectronics and LCD manufacturing are
gearing up for the next generation of devices that demand tighter densities, better electrical efficiency, higher speed and
better quality. We focus here on the differences between processing with nanosecond and picosecond pulses on Silicon
and on alumino-borosilicate glass.
Singulation of devices from processed silicon wafers has historically been accomplished by cutting with mechanical
saws. Current trends toward the use of thinner wafers coated with mechanically weak dielectrics reduce the speed and
quality of mechanical cutting processes. The speed of laser cutting, which has previously been too low for practical
implementation, may be increased significantly by altering the beam characteristics of a frequency-tripled Nd laser to
produce an elliptical focused spot. Using a commercially available laser, the cutting speed exceeded that of mechanical
cutting. The fracture strength of the edges as measured by bend testing is higher for elliptical beams than for round ones.
Sealed CO2 lasers at <500 watts power are widely used for cuttng and drilling, but their welding performance is less well known. The welding trials reported here address this by identifying welding performance for certain widely used ferrous and non-ferrous materials. Welds were made at a fixed average power and a range of laser parameters over a range of weld speeds. Conventional metallographic techniques were used for assessing weld dimensions and weld quality.
Aluminum nitride (AN) is beginning to replace alumina as a substrate and heat sink for electronic circuits. The thermal conductivity of A1N, about 8 times that of alumina, is the primary reason for its selection in these applications. While beryllium oxide has even higher conductivity, concerns about that material's toxicity reduce its appeal. Alumina is easily scribed and cut with carbon dioxide lasers. The high thermal conductivity that makes AIN useful, however, makes it difficult to machine with a laser because the material can absorb considerable incident energy without melting or vaporizing. Process settings that produce good results with alumina are not suitable for AIN. It is therefore necessary to develop a new processing regime for aluminum nitride. We cut 0.7 mm thick aluminum nitride sheet with a carbon dioxide laser using a large matrix of process variables and examined the resulting edges for surface quality, microcracking, aluminum deposition and recast. With this information, we defined the volume in process space where effective processing can be accomplished.
Laser processing of glass components is of significant commercial interest for the optoelectronics and telecommunications industries. In this paper, we present laser processing techniques using microsecond, nanosecond, and femtosecond lasers for machining of glass. Surface structures, mainly groove geometries, are generated with a diode-pumped solid-state nanosecond pulsed UV laser operating at 266 nm, a Q-switched CO2 laser operating at 9.25 μm, a CO2 laser operating at 10.6 μm and the femtosecond pulsed laser operating at 800 nm. Grooves are cross-sectioned and viewed with a focused ion beam (FIB) microscope. The resultant material structures are examined with respect to the differences in time scale and the appropriateness of each laser type for particular processes.
Laser processing of glass components is of significant commercial interest for the optoelectronics and telecommunications industries. Several fundamentally different interactions are employed to produce active components: after generating optical waveguides and gratings inside glass, external features must be machined in the modules to allow light to couple into the functional regions. In this paper, we present laser processing techniques using microsecond, nanosecond, and femtosecond lasers for surface and sub-surface glass modification. A regeneratively amplified Ti-Sapphire laser operating at a near-IR wavelength with femtosecond pulses and a 250 kHz repetition rate is used to generate 3-D optical waveguides and Bragg gratings in glass and silica substrates. Surface structures, mainly groove geometries, are generated with a diode-pumped solid-state nanosecond pulsed UV laser operating at 266 nm, a Q-switched CO2 laser operating at 9.25 μm, a CO2 laser operating at 10.6 μm and the femtosecond pulsed laser operating at 800 nm. The material interactions are examined with respect to the differences in time scale and the appropriateness of each laser type for particular processes.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.