Gregory J. Cowle

Multiple wavelength generation with Brillouin/erbium fiber lasers

Brillouin/erbium fiber lasers, which have recently been demonstrated, operate with a combination of Brillouin gain and gain in erbium-doped fiber. In this letter, we describe techniques for cascading the Brillouin/erbium fiber laser to generate optical combs, and experimentally demonstrate optical comb generation. Internal and external cascading techniques are demonstrated. The line spacing in the combs is approximately 10 GHz, with operation in the 1550-nm region.

Properties of Brillouin/erbium fiber lasers

The unique combination of two gain media in Brillouin/erbium fiber lasers results in distinctive properties of such sources. The paper describes in detail the output and efficiency properties of Brillouin/erbium fiber lasers, from experimental results and a theoretical model. Single longitudinal mode output with linewidth <10 kHz was measured, with a 4-nm tuning range with the Brillouin pump wavelength. Frequency pulling associated with the Brillouin gain was investigated and observed to increase linearly with the Brillouin pump power.

Bidirectional 10-GHz optical comb generation with an intracavity fiber DFB pumped Brillouin/erbium fiber laser

We present multiwavelength and bidirectional operation of a novel Brillouin/erbium fiber ring laser. Multiwavelength operation is seeded by an Er/sup 3+/:Yb/sup 3+/ fiber distributed-feedback (DFB) laser inserted into the ring cavity. We realized lasing at up to eight wavelengths separated by 10.6 GHz.

Optimization of wavelength tuning of erbium-doped fiber ring lasers

The dynamics of erbium-doped fiber ring lasers undergoing wavelength tuning is examined. The relaxation oscillations and mode build-up time are characterized. An all-optical damping technique which is capable of complete elimination of relaxation oscillations is analyzed, and measurements on a tunable erbium-doped fiber lasers are reported. An analytical solution is derived for the mode build-up time of tunable fiber lasers. Limiting parameters for the design of a high-speed tunable fiber laser are identified. An equalization technique for obtaining uniform switching speed is described.

Single-polarization operation of fiber distributed feedback (DFB) lasers by injection locking

This paper investigated injection locking characteristics of a fiber distributed feedback (DFB) laser operating in dual polarizations, and found that it could operate in a single polarization by injection locking. The locking bandwidth was less than 10 MHz, much narrower than DFB laser diodes as a consequence of longer cavity length and resulting longer photon lifetime. As a more practical method to realize single-polarization operation of the fiber DFB laser, we proposed self-injection locking with a polarization-selective optical feedback composed of a mirror and a polarizer, and demonstrated a stable single-polarization operation.

Optical gain control of erbium-doped fiber amplifiers with a saturable absorber

Optical gain control (OGC) can be used to lock the inversion of an erbium-doped fiber amplifier (EDFA), assuming that the gain medium is homogeneous. However, EDFs exhibit certain degrees of spectral hole burning. As a result, when the OGC laser power and the spectral-hole depth at the laser wavelength change, the inversion of the EDFA changes accordingly with a fixed OGC cavity loss. In this work, a saturable absorber is placed in the OGC laser cavity to adjust the cavity loss dynamically and compensate the gain tilt caused by the OGC laser spectral hole burning. It is demonstrated that the steady state gain variation of a surviving channel in an optically gain controlled EDFA is improved from 1.3 dB (with a fixed loss) to 0.4 dB (with a saturable absorber in the cavity). The transient response of this gain control scheme is also discussed.

Suppression of relaxation oscillations in tunable fiber lasers with a nonlinear amplified loop mirror

The concept of relaxation oscillation damping in a tunable fiber laser with a nonlinear absorber or loss element is demonstrated, using a dual-cavity erbium-doped fiber laser. A nonlinear amplified loop mirror was employed as the nonlinear loss element to facilitate damping. Experimental results exhibiting complete elimination of relaxation oscillations are presented.<<ETX>>

Multiwavelength, bidirectional Brillouin/erbium fiber ring laser pumped with an intracavity fiber DFB laser

Summary form only given. We present a novel configuration of a Brillouin Er-doped fibre laser (BEFL), in which Brillouin gain is initiated by an Er/sup 3+/,Yb/sup 3+/-doped fiber distributed feedback (DFB) laser in the ring cavity. The laser output features multiwavelength and bidirectional operation, with potential applications in Brillouin fiber-optic gyros as well as dense wavelength-division multiplexing (WDM).

Distributed-Feedback Ring All-Fiber Laser

Continuous-wave, low-threshold and 6.5 kHz linewidth single longitudinal mode operation is achieved in a novel distributed-feedback (DFB) ring all-fiber laser configuration, using an Er3+/Yb3+-doped phosphosilicate fiber. Self-Q-switching due to saturable absorption has also been observed in the DFB ring configuration using a heavily erbium doped germanosilicate fiber.

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.