Wan-k Seo

10 and 20 GHz optical combs generation in Brillouin/erbium fiber laser with shared cavity of Sagnac reflector

A novel operation scheme of a Brillouin/erbium fiber laser (BEFL) whose cavity consists of two metal-coated fiber planar mirrors (FPMs) and a Sagnac reflector is presented. Optical comb generation of both 10 and 20 GHz spacings is demonstrated by discrimination of the even order Stokes waves and the odd order Stokes waves. Theoretical analysis based on the reflection properties of the Sagnac reflector yields a good description of the multi-wavelength BEFL characteristics.

Stimulated Brillouin scattering suppression using cross-phase modulation induced by an optical supervisory channel in WDM links

A stimulated Brillouin scattering (SBS) suppression method is proposed for wavelength-division-multiplexed (WDM) links, based on the cross-phase modulation (XPM) effect induced by an optical supervisory (SV) channel. Since the XPM on each signal channel is induced by the 52-Mb/s optical SV channel, the SBS suppression is nearly insensitive to WDM signal channels. We experimentally demonstrate that the proposed method can increase the SBS threshold and reduce the error floors irrespective of the bit rate, channel power, channel wavelength, and channel spacing of the WDM channels.

Bidirectional DWDM transmission using a beat-frequency-locking method

In order to achieve the dense-wavelength-division multiplexing (DWDM) in bidirectional optical transmission systems, we present a beat-frequency-locking method to stabilize the relative channel frequency offset between two communicating nodes. Using the proposed method, we demonstrate a bidirectional DWDM transmission having 50-GHz channel spacing in both 2.5- and 10-Gb/s bit rates.

Dynamic Gain Control of Booster Amplifier (EDFA) Using an Optical Supervisory Channel Power Adjustment in Wavelength-Division-Multiplexing Transmission Systems

We present a simple dynamic gain control for a booster amplifier (EDFA) with an optical supervisory channel power adjustment in wavelength-division-multiplexing (WDM) transmission systems. We performed gain clamping and power clamping of an EDFA in optical links. We transmitted 10 Gb/s WDM signals and a 155 Mb/s supervisory signal through a 320 km single mode fiber.

Arrayed-waveguide grating with branched outputs for simultaneous multichannel monitoring purposes

We propose an arrayed-waveguide grating (AWG) that has branched output waveguides for simultaneous multichannel monitoring purposes. The transmittances of two adjacent branched output waveguides are slightly different from each other. Thus, we can obtain crossover wavelengths, where the transmittances of adjacent output waveguides are the same with much smaller insertion losses than those of conventional AWGs. As a result, the proposed device can accurately monitor wavelength-division-multiplexed channel wavelengths in the presence of the amplified-spontaneous-emission noise.

Multi-wavelength Brillouin/erbium fiber laser discriminating even/odd order Stokes waves

Summary form only given. Multi-wavelength Brillouin/erbium fiber lasers (BEFLs) with several kinds of cavity configurations have been recently reported for a number of applications. An erbium-doped fiber amplifier (EDFA) in a laser cavity of the BEFL compensates the resonator loss that is critical in ordinary Brillouin fiber lasers (BFLs), while still originating lasing action from the nonlinear Brillouin gain. We describe a novel operation scheme of a BEFL whose cavity comprises two metal coated fiber planar mirrors (FPMs) and a Sagnac reflector. By the adjustment of polarization controllers (PCs) in the Sagnac reflector, both 10 GHz and 20 GHz multi-wavelength operations can be supported.