Abstract: A metallic gas cell including a metallic casing having an input open end and an output open end, and a opening located therebetween. The metallic gas cell also includes an input and an output optical modules, each being respectively hermetically attached to one of the corresponding open ends. The metallic gas cell includes sealing means for sealing each of the optical modules in one of the corresponding open ends, thereby defining an airtight cavity in the casing when the opening is sealed. The metallic gas cell also includes an optical energy absorbing gas being enclosed within the cavity. The metallic gas cell is advantageously modular for allowing the use of various input or output modules such as windows, lenses, lasers, photodetectors, and fiber collimators. The gas cell also allow multi-cavity gas cell that that use a minimum number of components and cells to be obtained. Moreover, by its specific construction, the present gas cell prevents alignment issues.

Abstract: An adjustable positioning mechanism for positioning an optical element relatively to a second element is provided. The adjustable positioning mechanism comprises a reference plate having a predetermined shaped socket providing a reference mating surface, and a mobile member for holding the optical element. The mobile member has a shaped mating portion at least part of which is defined by a spherical surface adapted for fitting into the reference plate socket and abutting against the reference mating surface, thereby providing a pivot type of joint between the reference plate and the mobile member. The adjustable positioning mechanism is also provided with a deformable maintaining element connected to the mobile member acting against the reference plate and adapted to rotatively hold the mobile member and the reference plate together in cooperation with the pivot joint.