Experimental Demonstration of a Mode-Competing Multiline Resonant Laser

A multiline guided-mode resonance (GMR) filter is applied as a reflector to implement an external cavity laser. We design the resonant element using rigorous numerical methods and fashion an experimental prototype by thin-film deposition, patterning, and etching. A similar to 100-nm TiO2 grating layer on a similar to 170-mu m-thick glass slab supports thousands of resonant modes. We detect similar to 10 narrow resonance peaks within a similar to 10-nm wavelength range centered at the 840-nm wavelength. We apply this multiline GMR device to a gain chip and obtain several simultaneous resonant laser lines that compete for the gain. Precise tuning enables a stable laser line that can be selected from the multiple available resonant lines.