Abstract: An air-density-tuned interferometer includes: a hermetically sealed enclosure; a front window coupled to the hermetically sealed enclosure; an interferometer residing within the hermetically sealed enclosure; and a pressure changing device coupled to the hermetically sealed enclosure. The interferometer within the enclosure includes: a first glass plate optically coupled to the front window; a first reflective coating coupled to the first glass plate; a second reflective coating optically coupled to the first reflective coating; a second glass plate coupled to the second reflective coating; and a plurality of spacers coupled to the first and second glass plates, forming an optical interometric cavity therein. The pressure changing device manipulates the gas pressure within the cavity.

Abstract: The present invention relates to a microwave electronic device (1) comprising a metal enclosure (2) having a bottom (21) and a lid (23) and containing an electronic circuit board (3) disposed substantially parallel to said bottom and to said lid, said circuit board having: conductive bottom and top grounding layers (41, 42) respectively disposed on bottom and top faces (31, 32) of the circuit board, and perforations (7a) transverse to said faces of the circuit board and delimited by conductive walls (71) for electrically interconnecting said layers (41, 42). At least some of said walls (71) are electrically connected to the lid of the enclosure by conductive grounding members (8a). Each conductive member (8a) has a metal blade covered with a material (13, 13?) for absorbing microwaves.

Abstract: An optical assembly includes a lens unit having a first lens and a second lens arranged on a common optical path with substantially coincident optical axes. Each lens has a transmission region through which light passes from a first side to a second side of the lens, and a first and a second table region on the periphery of the transmission region. The table regions are flat surfaces positioned on the first and second sides of each lens. An optical element holding tube is butt-coupled to the first table region of the first lens. An optical element, such as a filter, is supported on the first element holding tube. A second lens support tube holds the first lens and the second lens at opposite ends, with the first element holding tube therebetween. The first and second lenses and the optical element are passively aligned and then fixed in place with optical adhesive at the butt joints.

Abstract: An optical resonant cavity (50) defined between two mirrors (13′, 40), one of which (40) is a variable pitch Bragg reflector grating, is characterized in that a parameter CS of variation of the Bragg wavelength of the grating is such that the cavity resonates continuously from a first optical frequency to a second optical frequency higher than the first optical frequency. The invention can be used in particular to produce broadband band-pass filters with steep flanks, broadband amplifiers with no gain fluctuation, and continuous emission spectrum lasers and light-emitting diodes.