Trefor J. Morgan

Widely tunable four-wave mixing in semiconductor optical amplifiers with constant conversion efficiency

The conversion efficiency and output signal-to-noise ratio (SNR) of single-pump four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs) is strongly dependent on frequency shift. We examine a scheme for FWM in SOAs that uses two orthogonally polarized pumps. We compare experimentally and theoretically the conversion efficiency and SNR of the orthogonal-pump scheme with single-pump FWM. The orthogonal-pump scheme has nearly constant conversion efficiency and SNR over the 4.5-THz range of frequency shifts measured. Experimental and theoretical results for the conversion efficiency and SNR of the orthogonal-pump scheme agree to within 3.5 dB.

All-optical wavelength translation over 80 nm at 2.5 Gb/s using four-wave mixing in a semiconductor optical amplifier

Wavelength conversion using conventional single pump four-wave mixing in semiconductor optical amplifiers is limited to wavelength shifts of a few tens of nanometers due to the decrease of signal-to-noise ratio with wavelength shift. In this letter, we demonstrate an 80-mn wavelength shift with four-wave mixing (FWRW) using two orthogonally polarized pumps. The power penalty at a 10/sup -9/ bit-error rate for a 2.5-Gb/s signal is less than 1.0 dB. This result demonstrates the large wavelength shift capacity of this (FWM) technique.

Transponder Dependence Issues in Asynchronous Delay-Tap Monitoring

Asynchronous delay-tap sampling is an effective method enabling monitoring of multiple optical impairments on live traffic. This letter addresses impairment measurement issues arising from transponder manufacturing variations and presents methods to mitigate this.

Passive optical equalization of wavelength converters based on four-wave mixing in semiconductor optical amplifiers

We demonstrate equalization of the frequency-shift dependent conversion efficiency of four-wave mixing (FWM) in semiconductor optical amplifiers (SOAs). The wavelength converter provides fixed input tunable output wavelength conversion for ten wavelength-division-multiplexing (WDM) channels with 100-GHz spacing. Equalization is achieved by using a fiber Bragg grating (FBG) at the output of the fixed input tunable output wavelength converter. This method provides constant conversion efficiency to within /spl plusmn/1.5 dB over all WDM channels and can be easily adapted to other types of wavelength conversion.

Optical frequency conversion by four-wave mixing in semiconductor optical amplifiers

In four wave mixing (FWM) in semiconductor optical amplifiers (SOAs) the nonlinear waveguide is sufficiently short for the waveguide dispersion not to affect mixing efficiency. Therefore, wide pump tunability is possible. This makes FWM in SOAs a very attractive optical frequency conversion technique for WDM optical fibre networks.

Measurement of PMD using the time-domain evolution of the Stokes vector

We demonstrate a PMD measurement technique for 10-Gbit/s signals using time domain evolution of Stokes vector with a low sampling-rate coherent receiver. An accuracy of 2ps DGD is achieved over 0 to 25 ps.

C-band to L-band shift of 80 mn (10 THz) using four-wave mixing in a semiconductor optical amplifier

We present the first demonstration of an 80-nm wavelength shift by four-wave mixing from the C-band to the L-band. The power penalty at 10/sup -9/ BER for a 2.5 Gb/s signal is less than 1.0 dB.