Wavelength conversion using four-wave mixing with two nondegenerated pumps in a wavelength-selectable laser

Abstract

We demonstrated four-wave mixing (FWM) with two pumps in a wavelength selectable laser to achieve a wide conversion bandwidth. Non-degenerated FWM with dual pumps in SOAs has been proposed to flatten the conversion efficiency variation accompanied with the variation of detunings between input signal and output conjugate. By utilizing a wavelength selectable laser, this complex scheme can be easily realized by a single device. We used a wavelength selectable laser, which consists of an 8-channel DFB laser array connected to an multi-mode interference (MMI) combiner with an SOA at its output. The DFBs had different lasing wavelengths with 3.18 nm spacing. We introduced a signal wave through one of the DFB lasers, and two of the lasers were used as pump sources. The wavelength of the signal and one of the pumps were fixed. The wavelength of the output conjugate was changed by switching to a different second pump laser. Conversion efficiencies between -14 and -16 dB were observed with wavelength detunings between 8 and 27 nm. An efficiency variation as small as 2 dB over a 2 THz frequency detuning range was achieved, in contrast to more than 5 dB variation in single pump schemes.

High efficiency, wide range and completely transparent wavelength conversion method using replicas generated by dual pump nearly-degenerated four-wave mixing in a Mach-Zehnder interferometer SOA

“…This is why completely transparent conversion is impossible in this case. Chirp characteristics are reversed, for example.Dual pump technique can overcome the problem of the dependence of conversion efficiency on detuning and wide range wavelength conversion has been achieved [2][3][4]. In dual pump FWM, the generated signals are phase-conjugated lights and replicas of the original signal.…”