Tunable and Switchable Erbium-Doped Fiber Laser Using a Multimode-Fiber Based Filter

Abstract

We demonstrated a compact tunable and switchable single/dual-wavelength erbium-doped fiber laser. The fiber laser can be tuned and switched from single-wavelength to dual-wavelength oscillation by using our recently proposed tunable comb filter. The comb filter consists of a section of multimode fiber (MMF) coiled into a polarization controller and two sections of single mode fibers (SMFs) to form a SMF/MMF/SMF structure, serving as a simple tunable all-fiber Mach-Zehnder interferometer. Due to the insertion of the MMF-based polarization controller (PC), an additional phase shift is introduced from the difference of the birefringence intensity in different dominant modes, which can be used to tune the fiber laser. In the experiment, by properly adjusting the PC, a tuning range of 9.3 nm can be achieved for the single-wavelength operation. Moreover, dual-wavelength operation with different free-spectral-ranges can be obtained. The tunable and switchable fiber lasers are of great importance for their applications in optical testing, optical fiber sensing, and signal processing.

Wavelength Tuning of Multimode Interference Fiber Lasers: A Review

“…A similar PC‐based stress‐optic implementation was reported by Khattak et al, in 2018, where they coiled a long MMI filter (1 m‐long) in a PC pad to tune an Er MMI fiber laser. [ 31 ] They achieved laser tuning over 9.3 nm, ranging from 1555 to 1565 nm, in CW operation and a single output. Finally, a more sophisticated implementation was reported by Zhang et al, in 2019, where they tuned an Er MMI fiber laser using two MMI filters fused together, each stressed by its own PC, to achieve ML operation.…”

“…Summary of the central wavelength and the tuning range of wavelength‐tuned MMI fiber lasers tracked over time. Squares (orange) markers indicate ytterbium MMI fiber lasers: a) Selvas et al [ 13 ] b) Anzueto et al [ 14 ] c) Mukhopadhyay et al [ 29 ] d) Chakravarty et al [ 30 ] Circles (green) markers indicate Erbium MMI fiber lasers: e) Castillo et al [ 15 ] f) Castillo et al [ 16 ] g) Walbaum et al [ 26 ] h,i) Ma et al, [ 21,22 ] j) Antonio et al, [ 20 ] k) Ahmad et al [ 28 ] l) Khattak et al [ 31 ] m) Li et al [ 34 ] n) Zhang et al [ 32 ] Triangles (purple) markers indicate Thulium MMI fiber lasers: o) Ma et al [ 23 ] p) Zhang et al [ 33 ] q) Li et al [ 27 ] r) Ibarra et al [ 24 ] s,t) Sakata et al [ 25 ] u) Li et al [ 35 ] v,w) Sakata et al [ 36 ] The diamond and down triangle indicate exceptional cases where special light sources were used for Erbium, x) Antonio et al, [ 20 ] and Thulium, y) Yan et al [ 37 ] , respectively (see text for details).…”

Gigahertz Harmonic Mode‐Locked Fiber Laser Based on Tunable SMS Ultrafast Optical Switch

“…In general cases where nonlinear effects need to be considered, the phase shifts introduced by self‐phase modulation (SPM) and cross‐phase modulation (XPM) effects will change the self‐imaging beat length in GIMF varying the power coupling efficiency of the light from GIMF to SMF, which reveals the temporal intensity discrimination required for mode‐locking. The multimode light field distribution along the GIMF can be expressed as: [ 28–30 ] is the mode expansion coefficient, β 1 and are the propagation constants of fundamental mode and the n th excited mode respectively. When the length of GIMF meets odd integer times of the half beat length, ( m is an odd integer), the condition of the intensity discrimination can be satisfied, [ 24 ] Hence, all the modes satisfy , , , which can be written as: λ 0 is the central wavelength, L is the length of GIMF.…”

Tunable optical fiber cascade filter by magneto-optical effect

“…The structure is widely used as senor (Tian et al, 2018, AL-Janaby and AL-Dergazly, 2020, fiber filter (Zhang et al 2020, Álvarez-Tamayo et al, 2016, Chakravarty et al, 2017, recently, it is used as filter in CW optical parametric oscillation (OPO) cavity (Yu et al, 2020, Tang et al, 2019 since the nonlinear effect require low loss filter. The filter is used to tune Er (Khattak et al 2018, Yuxin et al, 2018, Walbaum and Fallnich, 2011 , Yb (Zhang et al, 2012, Sánchez et al 2006, Selvas et al 2005, and Tm (X. , Li et al, 2016, Zhang et al, 2015 doped fiber laser due to that the cascade filter central wavelength can be modified to operate at any central wavelength.…”

“…A. Khattak et al (Khattak et al 2018) used the SMS structure as a comb filter to obtain tunable and switchable, single and dual wavelength EDFL the tuning was 9.3 nm by modifying the PC. N. Li et al (Li et al, 2016) propose the largest tunable mode locked TDFL by using SMS filter with tunability about 100 nm by mechanical bending.…”