This work presents a numerical study of a W-type index chalcogenide fiber design for Mid-Infrared (MIR) supercontinuum (SC) generation beyond 10μm. Our fiber design consists of a Ge15Sb15Se70 glass core, a Ge20Se80 glass inner cladding and a Ge20Sb5Se75 glass outer cladding. These chalcogenide materials have the advantages to broaden the spectrum to 12μm, due to their low material absorption. The optical mode distribution of the chalcogenide fiber is simulated by a finite element method based on edge elements. With a 6 μm core diameter and a 12 μm inner cladding diameter, the proposed fiber design exhibits flat anomalous dispersion in the wavelength range (4.3-6.5μm), with a peak of about 7ps/(nm.km). The position of the second zero-dispersion wavelength (ZDW) can be easily and precisely controlled by the inner cladding size and should be shifted to around 7μm for a 18 μm inner cladding diameter. This design is more suitable for a pump wavelength at 6.3μm which is in the anomalous dispersion regime between two ZDWs and can broaden the spectrum due to the soliton dynamics. Our fiber design modelling shows that the nonlinear parameter at 6.3μm is 0.1225W−1 m−1, when using a nonlinear refractive index nNL=3.44 ×10−18 m2W−1, and the chromatic dispersion is D = 3.24ps/(nm.km). Compared to previously reported step-index fibers, the proposed W-type index chalcogenide structure ensures single mode propagation, which improves the nonlinearity, flattened dispersion profile and reduces the losses, due to a tight confinement of the mode within the core.
This work is novel in that it explains the modeling and simulation of a thulium-doped fiber amplifier (TDFA) in a reconfigurable wavelength division multiplexing (WDM) system operating at 2 μm. We use the optical gain-clamping technique in order to control gain amplification and eliminate deleterious channel power fluctuations resulting from input power variation at the TDFA. The investigated system consists of 12 channels with -4 dBm total input power. Simulation results indicate that approximately1.5dB power excursion is produced after dropping 11 channels in unclamped-gain amplifier, and only 0.005 dB in a clamped-gain amplifier. Additionally, a clamped configuration brings the power excursion from 4.2 dB to under 0.08 dB, after adding 11 channels to the investigated system. Hence, optical gainclamping is a simple and robust technique for controlling the power transient in amplifiers at 2 μm.
Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks.
You are receiving this notice because your organization may not have SPIE eBooks access.*
*Shibboleth/Open Athens users─please
sign in
to access your institution's subscriptions.
To obtain this item, you may purchase the complete book in print or electronic format on
SPIE.org.
INSTITUTIONAL Select your institution to access the SPIE Digital Library.
PERSONAL Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.