Single-/dual-pulse repetition rate variable supercontinuum light source with peak wavelength around 1.7 µm using a modulated pump.

Abstract

A single-/dual-pulse repetition rate variable supercontinuum (SC) light source (SLS) with a peak wavelength of around 1.7 µm (SLS around 1.7 µm) is proposed and experimentally demonstrated. In our scheme, a 1.5 µm modulated pump source included a laser and an intensity modulator (IM). The pump source can generate pulse trains with different repetitions and pulse durations. A 1 km high nonlinear fiber (HNLF) was used as the nonlinear gain medium. A picosecond-pulsed SC signal was obtained by pumping the HNLF, and a wavelength division multiplexer was used for filtering residual pump. Additionally, a Sagnac loop was applied to create a multiwavelength pulse SC light source. The generated SC source covered from 1.59 to 1.96 µm, and its peak wavelength was around 1.7 µm. The single-/dual-pulse train can be produced and switched by adjusting the direct current bias and radio frequency driving voltages of the input signal to the IM. When the repetition rate of the generated pulse train was between 170 MHz and 2 GHz, the pulse duration of the dual-pulse train was between 60 ps and 180 ps. Additionally, the duty cycle of the dual-pulse operation was 40%. The single pulse SLS, around 1.7 µm, can be a choice to improve optical coherence tomography (OCT) performance, and the dual-pulse source will be a reference for laser drilling applications.