Author Affiliations
Institute of Ultrashort Pulsed Laser and Application, Faculty of Materials and Manufacturing, Beijing University of Technology, Beijing 100124, Chinashow less
Fig. 1. Schematic of light with different wavelengths reflected in CFBG
Fig. 2. Simulation result of reflective spectrum for CFBG
Fig. 3. Schematics of cascaded CFBG stretcher and series CFBG stretcher. (a) Cascaded CFBG stretcher; (b) series CFBG stretcher
Fig. 4. Simulated reflective spectra of three stage series CFBG stretcher
Fig. 5. Schematic diagram of inscription of optical path
Fig. 6. Reflective spectra of CFBGs before and after optimization of optical path and reflective spectra of CFBGs in cascaded CFBG stretcher. (a) Reflective spectra of CFBGs before and after optimization of optical path; (b) reflective spectra of CFBGs in cascaded CFBG stretcher
Fig. 7. Reflection spectra and broadband pulse structure of series CFBG stretcher before and after structure optimization (insets are schematic diagrams of CFBG arrangement in series CFBG stretcher). (a) Reflective spectra and (b) stretched pulses before structural optimization of series CFBG stretcher; (c) stretched pulses and (d) reflective spectra after structural optimization of series CFBG stretcher
Fig. 8. Spectra and pulse of fiber source, and pulse after cascaded CFBG stretcher. (a) Output spectra and (b) pulse of fiber source; (c) pulse after cascaded CFBG stretcher (inset: pulse sequence)
Fig. 9. Spectra of fiber laser and spectra and pulses after connection with series CFBG stretcher. (a) Spectrum of source and spectra after direct connection and reverse connection with series CFBG stretcher; (b) pulses after connection with two series extenders (inset is pulse train); pulses of reverse connection with series CFBG stretcher (c) before and (d) after exposure optimization
Stretcher type | Dispersion D /(ps·nm-1) | Bandwidth Δλ /nm | Stretching accumulation D·Δλ /ps | Advantage | Disadvantage |
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Cascaded CFBGs | n·D' | Δλ' | n·Δλ'·D' | Adjustable stretching accumulation | Large loss | Series CFBGs | D' | n·Δλ' | n·Δλ'·D' | Adjustable stretching accumulation | Complex fabrication | Single CFBG | D' | Δλ' | Δλ'·D' | Low loss | Unadjustable stretching accumulation |
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Table 1. Performance comparison among different types of CFBG stretchers based on phase mask with fixed parameters