Patent ID: 9720250
Date: 2017-08-01
CPC Classifications: G02B

Claim:
1. A tunable optical filter device, comprising: a first diffraction element oriented to differentially diffract light of different wavelengths of a beam of light incident thereupon from an input port; a lens located between the first diffraction element and the input port, whereby the beam of light incident on the first diffraction element from the input port is collimated a second diffraction element oriented to differentially diffract light of different wavelengths of the beam of light incident thereupon from the first diffraction element, wherein the second diffraction element is oriented relative to the first diffraction element such that a cumulative amount of angular dispersion from the first and second diffraction elements for portions of the beam of light incident upon the second diffraction element is less than an amount of angular dispersion from the first diffraction element for the portions of the beam of light incident upon the second diffraction element; a reflector that reflects the portions of the beam of light incident thereupon by the second diffraction element in an optical path between the input port and an output port; and an actuator connected to change a position of the reflector so that a selected range of wavelengths of the portion of the beam of light incident upon the reflector is reflected along the optical path from the input port to the output port.