Tunable Transmission Resonant Filter and Modulator With Vertical Gratings

Resonant filters in waveguides with vertical gratings have been realized on a silicon-on-insulator wafer. Two identical uniformly distributed Bragg reflectors with vertical gratings are separated by a quarter wavelength phase offset. Experimental studies show a broad stopband and a narrow transmission band which shifts with changing substrate temperature that is also illuminated by an external laser pump beam at 514-nm wavelength. Experimental results on a low-frequency thermal modulation using an external light source are also presented