Polarization properties of four-wave mixing in strained semiconductor optical amplifiers

Abstract

Abstruct-We present a theoretical and experimental study of the polarization properties of the four-wave mixing susceptibility of highly-strained multiquantum-well optical amplifiers and show how the intensity and polarization of the four-wave mixing signal depend on the polarization of the input waves. We demonstrate the validity of our model by generating a wavelength-converted signal having a polarization orthogonal to that of the pump wave at the output of the amplifier. In addition, we discuss the possibility of making the conversion efficiency independent of the input signal polarization by proper selection of the pump polarization.

Measurement of the interwell carrier transport lifetime in multiquantum-well optical amplifiers by polarization-resolved four-wave mixing

“…In this case, as shown in Ref. 10, modulation only occurs either through beating of the TE components of the input waves or, separately, through beating of their TM components. Furthermore, the TE ͑TM͒ component of the pump is then scattered only into a TE ͑TM͒ polarized FWM signal.…”

“…9 In a recent article 7 it was shown how this technique enables selective excitation and probing of adjacent quantum wells, and the effect of interwell transport was qualitatively observed. Here we apply the results of a subsequent detailed study of the polarization properties of FWM 10 to also obtain quantitative information. In particular, a fit of the experimental data to a simple model gives an estimated 16 ps for the interwell transport lifetime in the structure measured.…”

“…The prefactors R iikk in these equations account for wave propagation effects and can be regarded as independent of the detuning frequency over the small detuning range (Ͻ100 GHz͒ considered in this work. 10 A schematic representation of the polarization components of the input waves involved in the modulation and scattering processes in each type of well is given in Fig. 1.…”

Polarization-insensitive four-wave mixing in a semiconductor optical amplifier

“…FWM is generated by the beat between a signal and a strong pump and requires that signal and pump have the same polarization, even if the use of strained semiconductor quantum well structures may partially relax this constraint. 1 To date several methods have been proposed to circumvent this intrinsic limitation and obtain polarization-insensitive operation. For example, the method of polarization diversity uses two devices that independently process two orthogonal polarization states of the signal 2 but has the drawback that it requires two SOAs instead of one, and that any imbalance of the efficiency of the two converters acts to restore polarization sensitivity.…”

Measurement of the stimulated carrier lifetime in semiconductor optical amplifiers by four-wave mixing of polarized ASE noise

“…The measurement is based on polarization resolved, nearly degenerate FWM [4], [7] in an SOA where both TE and TM In the upper panel, the generation of carrier density modulation by beating of the TM components of the input waves is shown. This occurs only in the tensile wells.…”