Dmitrii Yu. Stepanov

Hybrid Brillouin/erbium fiber laser

We propose and demonstrate a novel hybrid Brillouin/erbium fiber laser that uses both Brillouin gain in singlemode optical fiber and gain in erbium-doped fiber. The lasing frequency was accurately determined by the Brillouin shift in single-mode optical fiber and was 10.35 GHz from the Brillouin pump. Large powers could be extracted because of incorporation of erbium-doped fiber in the laser resonator. An output power of 10 mW was measured at a wavelength of 1532 nm.

Correction of systematic errors in the fabrication of fiber Bragg gratings

We suggest a novel method for significant improvement of fiber Bragg grating (FBG) spectral characteristics based on compensation of repeatable errors during the grating writing process. The method is based on an open loop scheme in which a test grating is written first and then a corrected design is obtained and implemented by writing another (compensated) grating. The results are presented for a FBG dispersion compensator.

Multiwavelength operation of Brillouin/erbium fiber lasers with injection-locked seeding

Brillouin/erbium doped fiber lasers (BEFLs) have recently been demonstrated as a novel mode of operation of fiber lasers, using both the gain of an erbium-doped fiber (EDF) and Brillouin gain in single-mode optical fiber. BEFLs can be configured to produce laser combs, with potential applications in dense wavelength-division multiplexing. In this paper we present a different regime of operation of a BEFL, in which a signal is injection locked in a ring resonator, which then seeds the BEFL modes.

A new technique for measuring the group delay of chirped fiber Bragg gratings

In summary, a simple and inexpensive method for measuring the group delay of chirped gratings has been proposed and demonstrated. It, can be shown that this method can give, more generally, the group delay response of any grating, and is not limited to linear chirps.

Tuning range and efficiency of a Brillouin/erbium fiber laser

We report tuning range and efficiency measurements of a novel dual-gain medium Brillouin/erbium fiber laser which utilizes the Brillouin gain in single-mode optical fiber and gain in erbium-doped fiber. Analytical results on the efficiency of the laser are presented which fit well to the experimental results and allow for an intuitive interpretation of the observed properties of the laser efficiency, which varies according to the laser operating conditions. Tuning range of 4nm was observed upon tuning of the Brillouin pump wavelength.

Concept for monitoring fiber Bragg grating fabrication process

Complex coupling coefficient along a fiber Bragg grating under fabrication is derived from its complex reflection coefficient measured at a single wavelength thus offering a concept for a closed-loop grating fabrication system.

Pitch control in fabrication of Bragg gratings

We change the pitch of interferometrically written 1-dimensional periodic structures by adjusting the frequency shift between two interfering beams. This technique is applicable to fabrication of both planar and fiber Bragg gratings.