Abstract: A tunable optical filter system receives an optical signal, from an optical fiber. A predetermined wavelength is to be selected from the optical signal. The filter has a first and second aligned collimating lens, each lens having a mirrored surface separated by a gap. The first collimating lens collimates the light beam and outputs a collimated output beam via the its mirrored output surface to the opposing mirrored surface. A diaphragm coupled to a frame has a pair of piezo elements position the diaphragm to adjust the gap to select a predetermined wavelength signal from the collimated beam. A coupler samples a portion of the beam for a servo that responds to an input signal that identifies the wavelength to be selected. The servo provides a pathlength control signal to the piezo elements to coarse select the predetermined wavelength signal from the collimated output beam.

Abstract: A tunable optical filter system comprising an optical module receiving an input optical signal having at least a first and a second wavelength from which a predetermined wavelength is to be selected, and a first and a second axially aligned collimating lens. Each collimating lens has a mirrored surface separated by a gap distance to form a gap. The input fiber couples the light beam into the first collimating lens. The first collimating lens collimates the light beam and outputs a collimated output beam via the its mirrored output surface into a gap between the mirrored surfaces. A diaphragm is coupled to the frame. The diaphragm has a pair of piezo elements. The second collimating lens is mechanically coupled to and positioned by the diaphragm to adjust the gap to select a predetermined wavelength signal from the collimated output beam.

Abstract: The rugged filter/switch cavity includes at least a two section low thermal expansion glass tubular frame, each section with a highly polished edge for abutting engagement and rigid gripping by electrostatic attraction to maintain the cavity integrity. Each frame section supports a multi-layer low loss thin film mirror in opposing relation to define the cavity gap. One mirror is fixed in the first section and the other mirror is carried by a diaphragm portion of the other section for axial movement toward and away from the first mirror to tune the cavity to different frequencies. Coaxially aligned optical fibers, affixed to each section by flexible epoxy, guide light from a broadband source including, one or more signals, into the first section, through the first mirror and back and forth between mirrors until the cavity is resonant to a signal to be selected which signal then exits the cavity via the second mirror and the other optical fiber.

Abstract: Disclosed herein is a Pathlength Control Assembly for Ring Laser Gyroscope comprising, in a preferred embodiment, a mirror, coupled to a mirror housing including a mirror post, wherein the mirror is mounted on (or is an integral part of) an axially deflectable membrane of the housing. A pair of piezoelectric transducers are responsive to an electronic input signal and mounted to a backing plate. The transducers sandwich the backing plate and deform the backing plate to drive the mirror post to axially deflect said membrane. In this manner, the backing plate serves a dual function to both support the piezoelectric elements and drive the mirror post.