Abstract: There is provided a complex frequency response filter providing a frequency response having a desired shape. A first complex frequency response filter includes a first and a second reflecting surfaces defining a resonant cavity therebetween. Each of the reflecting surfaces respectively has a predetermined surface finish providing a given reflectivity, therefore providing resonances with a predetermined shaped frequency response of a predetermined amplitude and of a predetermined periodicity. Those frequency responses can then be summed to generate an arbitrarily complex spectral response. In another embodiment, the complex frequency response filter includes a transmission medium and a first and a second reflecting surfaces defining a resonant cavity therebetween.

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.

Abstract: A method and a system for filtering a user light beam using a periodic filter having a frequency response stabilized at an absolutely calibrated value are provided. A primary light beam is generated by a tunable laser source and portions thereof are filtered by an absolute reference filter and the periodic filter. First the frequency of the laser source is automatically locked on the absolute reference filter, and then the frequency response of the periodic filter is locked relative to the frequency of the laser source. The frequency response of the periodic filter is therefore continuously maintained at the proper calibration. User input and output are provided to pass the user light beam through the stabilized periodic filter independently of the filter stabilization process. A broadband absolutely calibrated optical source and a method for absolutely calibrating an optical spectrum analysis device are also provided.

Abstract: A method and a system for filtering a user light beam using a periodic filter having a frequency response stabilized at an absolutely calibrated value are provided. A primary light beam having a tunable frequency is generated by a tunable laser source, and then split into first and second beams respectively sent to an absolute reference filter and the periodic filter. The signal from the absolute reference filter is first used for automatically locking the frequency of the tunable laser source relative to a selected absorption features of the absolute reference filter. Once the laser source is locked, the frequency response of the periodic filter is stabilized using the filtered second beam, with a selected spectral feature of the periodic filter frequency response being locked relative to the frequency of the tunable laser source. The frequency response of periodic filter is therefore continuously maintained at the proper calibration.