RESUMEN
A 10 W level 976 nm single-frequency linearly polarized laser source was demonstrated with a two-stage all-fiber amplifier configuration. The continuous-wave output power of 10.1 W was obtained from the second stage amplifier by using a 20/130 µm single-mode, polarization maintaining, 1.5 wt. % ytterbium-doped phosphate double-clad fiber. This all-fiber single-frequency laser source is very promising for watt-level deep ultraviolet laser generation via frequency quadrupling.
RESUMEN
Organic photorefractive polymer composites can be made to exhibit near 100% diffraction efficiency and fast writing times, though large external slants are needed to project the applied field onto the grating vector. We show here that the use of interdigitated electrodes on a single plane provides similar performance to these standard devices and geometries but without a external slant angle. This new device's structure also greatly improves the diffraction efficiency and sensitivity compared to less slanted standard devices necessary for some real applications, such as holographic displays, optical coherence imaging, and in-plane switching.
RESUMEN
A method of imaging sub-0.5-µm-dense photoresist lines with the real-time scanning optical microscope by the use of elliptically polarized light is developed. The imaging method takes advantage of the fact that polarized light undergoes a change in polarization when reflected from a grating structure. A confocal scanning optical microscope is modified to image this light. The resulting images show an increase in the detected intensity of the light reflected from the substrate region of the grating. Increasing this signal level improves the ability of the microscope to make linewidth measurements on photoresist structures as small as 0.3 µm. Results from several different semiconductor substrates are presented. A brief review of the grating theory is presented to suggest possible origins for the increase in light intensity.