Design and fabrication of a spatial light modulator using thermally tunable grating and a thin-film heater.
We propose the application of a thermally tunable grating as a spatial light modulator. The grooves of a square-well grating are filled with a liquid whose refractive index depends on temperature. The variation of optical characteristics of such a grating with respect to temperature is investigated theoretically and also by simulation and experiment. A thin-film heater is then used as a heat source. The relation between intensity of the first order of diffraction versus power consumption of the thin-film heater is investigated. Finally, a thin-film heater with a desired pattern is placed at the surface of the grating to fabricate spatial light modulator. By applying electrical current to different elements of the thin-film heater, the fabricated device can project a desired pattern on a screen using a 4f imaging system. The restrictions of such a device are discussed and another structure is proposed and discussed by numerical calculations to increase the ability of the device.
Laser and Plasma Research Institute, Shahid Beheshti University, Evin, Tehran, Iran.
Mohammadreza
M
Riahi
Hamid
H
Latifi
Abbas
A
Madani
Ali
A
Moazzenzadeh