Systems and methods for generating spectrally compressed photons from broadband emitted photon pulses. The system can include an input coupling having a first coupling ratio and an output coupling having a second coupling ratio. The first coupling ratio is configurable and the second coupling ratio is fixed. A cavity can be connected to the input coupling and the output coupling. A controller in electrical communication with the coupling device can be configured to change the first coupling ratio of the input coupling.

Disclosed is an adjustable optical filter device. The device comprises a first glass thin film provided with a first mirror and a second glass thin film provided with a second mirror. The peripheries of the surfaces of the first glass thin film and the second glass thin film that have a mirror are bonded to each other by means of a bond to form a cavity between the mirrors. The first glass thin film or the second glass thin film is provided with a driving unit for controlling the relative displacement of the first glass thin film and/or the second glass thin film. The tunable optical filter device has better optical filtering performance than existing filter devices, has the performance of small size and lower driving voltage, and can be applied to devices having a limited size, such as miniature spectrometers, small or even mini hyperspectral cameras or mobile phones.

A process for creating a Fabry-Perot Cavity (FPC) sensor using Two-Photon Polymerization (2PP) includes: fabricating a mask directly on a cleaved tip of a fiber optic cable. The mask includes: a beveled central hole aligned over the core of the fiber optic cable, side extensions that extend radially beyond a cladding of the fiber optic cable. The process includes sputtering a first reflective coating over the mask and tip of the fiber optic cable, mechanically removing the mask using the side extensions, and fabricating a resonator cavity structure (RCS) using a 2PP process over the gold disc.