Tunable circularly polarized lasing emission in reflection distributed feedback dye lasers

Tunable circularly polarized lasing emission in reflection distributed feedback dye lasers.

A tunable circularly polarized distributed feedback (DFB) laser based on reflection grating configuration was realized in a solution of 4- (dicyanomethylene)-2-methyl-6-(4-dimethylaminostyryl)-4H-pyran (DCM) doped methanol. Chiral photonic DFB structures with tunable photonic bandgap were generated by controlling the state of polarization of the two interfering pump beams. The dual-peak lasing ...

3 Tunable Dye Lasers

Piezoacoustic modulation of gain and distributed feedback for quantum cascade lasers with widely tunable emission wavelength

Due to the piezoelectric properties of III–V materials, an acoustic wave propagating along the optical axis of a unipolar laser produces a periodic modulation of the carrier density and the optical gain, sufficient for providing distributed feedback ~DFB! with a mode suppression ratio exceeding 30 dB. In contrast to bipolar lasers, the piezoelectric modulation of unipolar carrier density is not...

Circularly polarized high-efficiency cholesteric liquid crystal lasers with a tunable nematic phase retarder.

A high efficiency dye-doped cholesteric liquid crystal (CLC) is demonstrated by optimizing the dye concentration and using an electrically tunable nematic liquid crystal (NLC) phase retarder. The state of polarization of laser emission in CLC lasers, contrary to our expectations, due to the refractive index mismatch at the boundaries is not exactly circular. A double-cell structure including a ...

Widely tunable distributed-feedback lasers with chirped gratings

A quasicontinuous tuning range of 65 nm at 3.2 m was obtained for continuous wave, single-longitudinal-mode operation at 77 K of an optically pumped distributed-feedback laser with a chirped grating. Interferometric lithography with spherical wavefronts was used to fabricate a large-area chirped grating whose period varied continuously in the direction of the grating lines. Tuning was achieved ...