We demonstrate a tunable external cavity laser consisting of a voltage-tuned liquid-crystal cladded subwavelength resonant grating filter placed directly in front of a semiconductor laser gain chip. The filter acts as a tunable wavelength-selective mirror. As the applied voltage to the filter changes from 0 to 22 V, the laser wavelength demonstrates a tuning range of 7 nm, which may be further increased. As the laser has simple cavity design and no moving parts, it can be low cost and easy to fabricate and assemble.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Electrical and Electronic Engineering
- Resonant waveguide grating filter
- Semiconductor lasers
- Tunable lasers