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.
Riahi
Mohammadreza
M
Laser and Plasma Research Institute, Shahid Beheshti University, Evin, Tehran, Iran.
Latifi
Hamid
H
Madani
Abbas
A
Moazzenzadeh
Ali
A