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.
Highlights
Stable erbium-doped fiber (EDF) lasers are attractive sources that have many applications, such as optical sensing, microwave photonics, optical testing, and optical communications [1]
Some of the techniques that have been used to guarantee a single-longitudinal-mode (SLM) operation in EDF lasers are related with the Rayleigh backscattering feedback [2] or the use of saturable absorbers (SA) to suppress multiple modes in the cavity [3]
Due to the low Rayleigh backscattering coefficient of the single mode fiber (SMF), high pump power levels for Raman amplification were initially needed for the operation of all random fiber lasers by using Raman gain
Summary
Stable erbium-doped fiber (EDF) lasers are attractive sources that have many applications, such as optical sensing, microwave photonics, optical testing, and optical communications [1]. [5], artificially controlled backscattering (ACB) techniques that do not require Raman amplification or technical conditions and processes as complex as those required to fabricate, for example, random fiber gratings (RFG) [5] have been demonstrated They can generate a distributed mirror using the random feedback from Rayleigh scattering [6]. An approach of introducing strong backscattering as well as decreasing the pump power threshold and shorten the cavity length of fiber lasers is shown in this work Another remarkable advantage of this distributed reflector is that can be used as a saturable absorber, leading to the generation of tunable and switchable single longitudinal-mode laser emissions. Single and multiple single-mode laser emissions have been achieved using this new kind of reflecting saturable absorber; with average measured optical signal to noise ratios (OSNRs) of 45 dB
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have