Experimental study of an in-fiber acousto-optic tunable bandpass filter for single- and dual-wavelength operation in a thulium-doped fiber laser.

A tunable single- and dual-wavelength thulium-doped all-fiber laser is demonstrated based on the implementation of an in-fiber acousto-optic tunable bandpass filter (AOTBF). The AOTBF is fabricated to be operated in the 1.9 µm region, and takes advantage of the intermodal coupling effect produced by traveling flexural acoustic waves in an optical fiber.

Broadband tuning of a long-cavity all-fiber mode-locked thulium-doped fiber laser using an acousto-optic bandpass filter.

A long-cavity passively mode-locked thulium-doped all-fiber laser is reported incorporating a tapered acousto-optic tunable bandpass filter (AOTBF). The operation of the AOTBF relies on the intermodal coupling between core and cladding modes when a flexural acoustic wave propagates along an 80 μm tapered fiber. The filter works in transmission and exhibits a 3 dB bandwidth of 9.

Long cavity ring fiber mode-locked laser with decreased net value of nonlinear polarization rotation.

We investigate a new configuration of a mode-locked fiber laser by using a nonlinear polarization rotation-based design to generate soliton pulses with low repetition rate. Unlike with previously reported configurations, we introduce a Faraday mirror after the first half of the cavity length to counteract the nonlinear polarization rotation effects. The total cavity length is 437 m including a 400-m long twisted SMF-28 fiber.

Single and dual-wavelength noise-like pulses with different shapes in a double-clad Er/Yb fiber laser.

We report an experimental study of passive harmonic mode-locking in an all-fiber switchable dual-wavelength Er/Yb double-clad laser. The proposed scheme supports single- and dual-wavelength operation of mode-locked pulses with rectangular, h-like and trapezoidal shapes in a noise-like pulse regime. Single-wavelength emissions at λ = 1545.

Abrupt-tapered fiber filter arrangement for a switchable multi-wavelength and tunable Tm-doped fiber laser.

A switchable and tunable multi-wavelength Tm-doped fiber laser is successfully demonstrated using a filter constructed with two tapered fiber elements in the cavity. The proposed system design uses a low-cost simple filter that allows stable dual, triple, quadruple, and quintuple-wavelength emission operation in the region around 1.9 μm.