Laser modulation and Q-switching using an inverse fabry-perot filter

摘要

A laser includes an external modulation device including two spaced-apart wire-grids. The device has a reflectivity peak at a wavelength dependent on the spacing between the wire grids. The device is arranged to reflect and transmit radiation received from the laser. The reflected and transmitted radiation are modulated by varying the spacing between the wire-grid polarizers. The device may be used as an end mirror or a fold mirror of a laser resonator and operated as a Q-switch for the laser resonator. Q-switching is accomplished by varying the reflectivity of the device at the lasing wavelength from below to above a threshold reflectivity value for lasing.