Wavelength Tuning by Bending a Flexible Photonic Crystal Laser

This study demonstrated mechanical wavelength fine-tuning of a flexible photonic crystal (PhC) laser. A triangular PhC structure was fabricated in an InGaAsP layer on top of a polydimethylsiloxane substrate. Experiments showed two lasing modes at symmetry points K and M in the first PhC band. The laser structure was bent along the Γ-M direction and the lasing wavelength was fine-tuned by varying the bending radius. The lasing wavelength shift is attributed to PhC lattice distortion and its tuning behavior corresponds with the simulation results. This ultra-small, wavelength-tunable laser could function as a unique light source for integrated optoelectronic circuits.