Single Longitudinal Mode Lasers by Using Artificially Controlled Backscattering Erbium Doped Fibers

Abstract

In this work, we propose and experimentally demonstrate a new distributed short linear cavity fiber laser. At one of the cavity ends, fabricated by a commercial femtosecond fiber laser chirped pulse amplifier, an artificially controlled backscattering erbium doped fiber section has been connected. This distributed reflector acts also as a saturable absorber, leading to the generation of tunable and switchable single longitudinal-mode laser emissions. The distributed reflector consists of 9 micro-drilled sections of about 1cm each one and randomly spread throughout 2 meters of highly doped erbium fiber. The total length of the fiber laser is 9.5 m and the laser shows a single mode behavior at all the emitted wavelengths. Using this new kind of reflecting saturable absorber, single and multiple single-mode emissions can be obtained. The achieved laser presents a pump threshold as low as 45 mW and shows up to 8 different single-mode emission lines with an optical signal to noise ratio of 45dB.

High Performance Fiber Laser Resonator for Dual Band (C and L) Sensing

“…The FLM, at the right side of the structure, comprises another optical circulator (CIR3) in which ports 1 and 3 are connected to a variable optical attenuator (VOA). This mirror serves as a reflector of the resonator while allowing the fine tuning of its OSNR as well as lasing stability [15]. Once the recirculating signal reaches the third port of CIR2, it is guided through ports 1 and 2 of CIR1 to end at an optical coupler (OC).…”

“…Trying to address the lack of L-band sensing fiber lasers as well as the complexity and cost of achieving SLM operation, in this work we propose a high performance ACBFR assisted fiber laser resonator for dual band (C and L) sensing. To the best of our knowledge, this is the first scheme that achieves highlystable SLM operation by employing an ACBFR as short as 15 mm, reducing the previously reported case to less than 1 % in length [15]. Moreover, due to the pseudo-random nature of the designed reflector compared to the well-known FBGs, the resonator proposed in this work can be used to measure in different bands with comparable performance.…”

“…Citation information: DOI 10.1109/JLT.2022.3170124, Journal of Lightwave Technology 2 > REPLACE THIS LINE WITH YOUR MANUSCRIPT ID NUMBER (DOUBLE-CLICK HERE TO EDIT) < and as a sensor, tries to replicate the original physical phenomenon of random distributed feedback fiber lasers but without requiring long fiber spools as distributed reflectors. Although promising, recent studies have required artificially controlled backscattering fiber reflectors (ACBFRs) longer than two meters in length to achieve SLM behavior in laser sensing systems [15].…”

Wavelength-switchable L-band fiber laser assisted by random reflectors

“…It was also written on the axial axis of the MMF. Although this is a random fiber grating (MMF-RFG) [25], the almost total periodicity of the optical structure gives rise to Bragg resonances which, in the third order (m=3) and with an effective refractive index (neff) of around 1.4528, present reflections in the following spectral band:…”

Selectable and stable single-frequency fiber laser with flattened power range and sub-kHz linewidth output

“…Switchable and stable erbium-doped fiber (EDF) laser has turned into an important implement in many fields of application, comprising optical communication, microwave photonics, optical spectroscopy, bio-photonics, optical sensing, and instrumentation [1][2][3][4]. Besides, the EDF based lasers also have the appearances of narrow linewidth, single-longitudinal-mode (SLM), long coherence length, low phase noise and high optical signal to noise ratio (OSNR) [5].…”