Four-wave mixing in intra-cavity dual-wavelength fibre ring laser

Abstract

An intra-cavity four-wave mixing (FWM) in a dual-wavelength erbiumdoped fibre ring laser has been demonstrated where a 100 m-long dispersion-shifted fibre has been introduced as a nonlinear medium to pronounce the FWM effect in a 1550 nm window. The laser operates in the gain switched (pulse) mode for effectively achieving high power and increasing the intermodulation effect in the ring cavity. This scheme provides a simple and efficient way of archieving a dualwavelength source for various optical systems.Introduction: For future dynamic optical communication and various photonic applications such as spectroscopy, LiDAR (light detection and ranging), imaging, and advanced sensing technologies, generating new wavelengths plays a key role to facilitate the needs [1][2][3][4][5]. Especially, owing to the simplicity and efficiency, four-wave mixing (FWM) can be a more feasible candidate compared to other techniques based on phase and polarisation modulations [6]. Various schemes have been proposed using two (dual) wavelengths in order to address issues of polarisation insensitivity and higher conversion efficiency at larger wavelength spans using FWM methods in a dual-wavelength (mode) laser which can be used for an optical sensor (spectroscopy), THz-radiation generator, optical communications, and radio-over-fibre (RoF) systems [7,8]. For instance, the use of a dual-wavelength laser for FWM generation has been the subject of a several demonstrations: a two-photon-state has been generated via FWM in optical fibres [9]; FWM occurred using dual-wavelength in an electro-absorption modulator (EAM) [10]; FWM can be generated in a dual-wavelength semiconductor laser [11]; fibre FWM was implemented between a dual-wavelength fibre laser and the modulated optical carrier [12]; wavelength conversion was proposed based on FWM using an SOAwith dual-wavelength (employing two separate sources) [13].In this Letter, a dual-wavelength fibre ring laser with cascaded fibre Bragg grating is proposed, which incorporates a dispersion-shifted fibre (DSF) to effectively generate four-wave mixing in the fibre cavity at the 1550 nm range. The fibre laser can independently operate as a dual-wavelength source in a continuous-wave (CW) mode and as an efficient wavelength converter based on FWM owing to the parametric phenomenon by the nonlinearity of the DSF at gain-switched mode having an enlarged pump source power and extended effective cavity length.

Multi-wavelength fiber laser generation by using optical wavelength conversion

“…However, the line spacings of these multi-wavelength laser sources are too narrow for some applications. Four-wave mixing (FWM) in multi-wavelength fiber laser sources, based on the Kerr effect, can provide an alternative option for coping with this problem [27][28][29][30].…”

S + C + L Band tunable wavelength conversion using FWM dual‐wavelength fiber laser in a highly nonlinear fiber

“…Their range is limited to 40 nm only. As well as SOAs, a 100 m length of dispersion shifted fiber is also used as the nonlinear medium with a dual‐wavelength fiber laser as the pump and signal source [11]. Their wavelength conversion range, however, is only limited to the C‐band region.…”