Abstract
Broadband laser light sources in the mid-infrared region attract enormous interest due to the plethora of applications they are enabling, including multispecies trace gas detection, free-space communications, and infrared countermeasures. Key to the progress in supercontinuum generation has been the wide availability of fiber-based near-infrared and bulk-optic mid-infrared pump sources and suitably engineered nonlinear media capable of supporting high-brightness supercontinua. A large proportion of the system complexity relates to the pump source itself with free-space systems based on parametric conversion being the most common for the generation of long-wavelength supercontinua. In an effort to realize all fiber and all mid-infrared supercontinuum sources, we combine a recently developed 2.9 µm ultrafast fiber laser based on holmium with an environmentally stable, polymer-protected all-chalcogenide tapered fiber. By launching 230 fs, 4.2 kW peak power pulses into the As2Se3/As2S3 tapered fiber, we demonstrate a spectrum spanning from 1.8 to 9.5 µm at the −20 dB points with an average power of more than 30 mW. This >2 octave-spanning supercontinuum is a crucial step toward robust mid-infrared broadband sources required for future field-deployable instruments.
Highlights
Supercontinuum sources emitting in the mid-infrared (2–20 μm) have reached a high level of performance, with demonstrations of systems with wide bandwidth and high-power spectral density [1,2,3,4], low threshold power [5,6], and in photonic chip integrated planar waveguides [7,8]
Most of the supercontinuum systems demonstrated so far have employed free-space laser systems based on nonlinear optics to produce ultrashort pulses in the mid-IR, which are subsequently coupled to a highly nonlinear waveguide
The nonlinear media used for supercontinuum generation have been extensively explored with devices ranging from step-index fibers [1,2,3,15], integrated waveguides in both silicon [7] and chalcogenide [8], as well as suspended-core [16] and tapered fibers [4,17,18,19,20]
Summary
Supercontinuum sources emitting in the mid-infrared (2–20 μm) have reached a high level of performance, with demonstrations of systems with wide bandwidth and high-power spectral density [1,2,3,4], low threshold power [5,6], and in photonic chip integrated planar waveguides [7,8]. Most of the supercontinuum systems demonstrated so far have employed free-space laser systems based on nonlinear optics to produce ultrashort pulses in the mid-IR, which are subsequently coupled to a highly nonlinear waveguide.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
