One KHz Order Narrow Linewidth Fiber Laser Using Rayleigh Backscattering Mechanism in an Additional Piece Optical Fiber

Abstract

A simple, low-cost, single-longitudinal mode, C-band narrow-linewidth optical fiber laser is presented based on the methodology of the Rayleigh backscattering (RBS). In this paper, a 1551 nm fiber ring laser is developed, and single-mode fiber (SMF) is added to compress the line width. When the SMF length of the RBS cavity is 120 m, the laser has better performance than that in other SMF lengths with a laser line width of 1.46 KHz with housing shield. The optical signal-to-noise ratio (OSNR) is 59.86 dB, and its maximum output power is 9.4 mW. It can quickly achieve the single longitude-mode operation by controlling the variable optical attenuator (VOA). The bit error rate at 10 Gb/s PRBS NRZ modulation is measured to be 10−9 when the optical receiving power is −16.2 dBm.

Stable wavelength-swept single-frequency erbium fiber laser in L-band tuning bandwidth

“…Then, to guarantee the SLM oscillation of the EDF ring laser, we also choose the same six wavelengths as above by employing the delayed self-homodyne setup for measurement [2]. The delayed fiber line of the MZI is set at 50 km long.…”

“…Most of the past studies used the multi-fiber-ring or added EDF-SA in the laser cavity to achieve SLM oscillation [1,2,4,13]. However, the proposed L-band EDF laser not only reaches the kHz linewidth, but also reaches the better OSNR output by the proposed simple MZI, compound-ring and EDF-SA in the bandwidth of 1568.0 to 1613.0 nm.…”

“…Erbium-doped fiber (EDF) lasers with stable single-longitudinal-mode (SLM) have interested more attention owing to their serviceable applications, such as the micro-wave-photonic, optical communication, optical wireless transmission, optics sensor, bio-photonic, and spectroscope [1][2][3][4][5]. To construct the EDF laser, the ringbased fiber cavity would be the simple and easy way [6].…”

“…Nevertheless, because of the longer fiber length and EDF's homogeneous broadening effect, the EDF laser could result in the multiple and unstable longitudinal-mode fluctuations [9]. To mitigate the dense longitudinal-mode variations, several associated methods have been proposed, such as utilizing the Mach-Zehnder interferometer (MZI) based comb filter [10], composite-fiber-ring configuration [11,12], saturable absorber (SA) based filter [13,14] and optical feedback injection effect [2,15]. Commonly, the most of EDF lasers operated in the C-band scope from 1528 to 1562 nm.…”