Bragg-grating-based all-fiber distributed Gires-Tournois etalons

Spatially distributed delay line interferometer based on transmission Bragg scattering

A novel approach for a delay line interferometer (DLI) based on transmission Bragg scattering is proposed. We have numerically and experimentally demonstrated for the first time, to the best of our knowledge, that a Bragg grating (BG) can deliver the functionality of a DLI in its transmission mode along a single common interfering optical path, instead of the conventional DLI implementation with two interfering optical paths. As a proof of concept, phase-modulated fiber BGs have been designed and fabricated, showing the desired functionality in the transmission mode of the BG. The proposed approach is applicable to any kind of BG technology, such as volume BGs, dielectric mirrors, silicon photonics, and other optical waveguide-based Bragg structures.

Capacitors go optical: wavelength independent broadband mode cavity

Fabry-Perot resonators or interferometers (FPI) have existed for a long time and act as light accumulators. However, their applications have been limited to the allowed resonance modes in the cavity, which are defined by the specific free-spectral range of the FPI. We show here a novel concept involving a light "capacitor" capable of accumulating light over a wide spectral range, at any given repetition frequency. This device is actually an FPI in which a high chirped mirror (chirped fiber Bragg grating or chirp multi-layer coated mirror) is added to remove the wavelength dependence of the mode resonances, enabling a single very large broad-band mode. This "modification" does not affect the amount of light which can be accumulated, i.e. it does not reduce the Q-factor of the cavity. We show here the theoretical concept of such a device and experimental results demonstrating this principle.

Fabry-Pérot cavity based on chirped sampled fiber Bragg gratings

A novel kind of Fabry-Pérot (FP) structure based on chirped sampled fiber Bragg grating (CSFBG) is proposed and demonstrated. In this structure, the regular chirped FBG (CFBG) that functions as reflecting mirror in the FP cavity is replaced by CSFBG, which is realized by chirping the sampling periods of a sampled FBG having uniform local grating period. The realization of such CSFBG-FPs having diverse properties just needs a single uniform pitch phase mask and sub-micrometer precision moving stage. Compared with the conventional CFBG-FP, it becomes more flexible to design CSFBG-FPs of diverse functions, and the fabrication process gets simpler. As a demonstration, based on the same experimental facilities, FPs with uniform FSR (~73 pm) and chirped FSR (varying from 28 pm to 405 pm) are fabricated respectively, which shows good agreement with simulation results.

Virtual Gires-Tournois etalons realized with phase-modulated wideband chirped fiber gratings

We propose and demonstrate novel virtual Gires-Tournois (GT) etalons based on fiber gratings. By introducing an additional phase modulation in wideband linearly chirped fiber Bragg gratings, we have successfully generated GT resonance with only one grating. This technique can simplify the fabrication procedure while retaining the normal advantages of distributed etalons, including their full compatibility with optical fiber, low insertion loss, and low cost. Such etalons can be used as dispersion compensation devices in optical transmission systems.

Dual-direction Gires-Tournois etalon based on a single complex fiber Bragg grating

We propose and demonstrate a single fiber Bragg grating-based Gires-Tournois (GT) etalon, which is realized by applying a complex apodization profile on a linearly chirped fiber Bragg grating. Such a GT etalon not only has a simplified fabrication procedure but also can operate in dual directions.

Reduction of collision-induced timing shifts in dispersion-managed quasi-linear systems with periodic-group-delay dispersion compensation

Periodic-group-delay (PGD) dispersion-compensation modules were recently proposed as mechanisms to alleviate collision-induced timing shifts in dispersion-managed (DM) systems. Frequency and timing shifts in quasi-linear DM systems with PGDs were obtained, and it is shown that significant reductions are achieved when even a small fraction of the total dispersion is compensated for by PGDs.

Tailored Gires-Tournois etalons as tunable dispersion slope compensators

We present a novel concept of a tailored Gires-Tournois etalon structure and show that such a device is useful for the fabrication of a dispersion-slope compensator with an almost arbitrary dispersion profile and also with tunability in the dispersion slope.

Transmissive in-fiber Fabry-Perot etalons as tunable dispersion compensators and dispersion-slope compensators

We report for what is believed to be the first time the use of transmissive fiber Bragg grating-based Fabry-Perot etalons for tunable dispersion compensation and dispersion-slope compensation. The resulting device has a number of advantages, such as low cost, ease of fabrication, full optical fiber compatibility, and simplicity.