Publication: Variable 1.7 �M TO 2 �M amplifier and fiber laser based on ase suppressed TDFA
Date
2017
Authors
Emami S.D.
Lee H.J.
Arabanian A.S.
Journal Title
Journal ISSN
Volume Title
Publisher
Nova Science Publishers, Inc.
Abstract
Thulium-doped fiber amplifiers (TDFA) operating around 1.9 �m provide the broadest gain spectrum of all rare-earth doped optical amplifiers. The amplified spontaneous emission (ASE) suppression method is one of the possible ways to shift functional amplification range and change operating laser wavelength. Partial ASE suppression methods involve suppressing a portion of the unwanted ASE spectrum so that the gain of the requisite transmission window can improve accordingly. This chapter describes low pass filter and its application for 1.7 �m to 1.9 �m band thulium-doped fiber amplifier (TDFA) and thulium-doped fiber laser (TDFL) based on photonics crystal fiber (PCF) partial ASE suppression. The low-pass long cut-off wavelengths of the proposed PCF were achieved by enlarging the air holes surrounding the doped core region. We show that the optimized PCF geometrical structures resulted in long cut-off wavelengths of 1.85 �m and 1.75 �m to achieve the intended transmission characteristics. The experimental loss spectrum has been verified through numerical transmission characteristics using fullyvectorial finite element method (V-FEM). Finally, the proposed optical low-pass filter was applied in a TDFA system to partially suppress the ASE in the 1.9 �m region. We also show that the ASE peak and operating laser wavelengths could be shifted towards shorter wavelengths by rescaling the opto-geometrical parameters of the PCF fibers. � 2017 Nova Science Publishers, Inc.
Description
Amplifiers (electronic); Fiber lasers; Fibers; Geometry; Low pass filters; Numerical methods; Photonic crystal fibers; Plasma diagnostics; Rare earth-doped fibers; Rare earths; Thulium; Amplified spontaneous emissions; Geometrical structure; Optical low-pass filter; Photonics crystal fibers; TDFA; Thulium doped fiber amplifiers; Thulium-doped fibers; Transmission characteristics; Fiber amplifiers