Optical parametric amplification, optical parametric generation, and optical pumping in optical fibers systems

Abstract

Embodiments described herein include a system for producing ultrashort tunable pulses based on ultra broadband OPA or OPG in nonlinear materials. The system parameters such as the nonlinear material, pump wavelengths, quasi-phase matching periods, and temperatures can be selected to utilize the intrinsic dispersion relations for such material to produce bandwidth limited or nearly bandwidth limited pulse compression. Compact high average power sources of short optical pulses tunable in the wavelength range of 1800 to 2100 nm and after frequency doubling in the wavelength range of 900 to 1050 nm can be used as a pump for the ultra broadband OPA or OPG. In certain embodiments, these short pump pulses are obtained from an Er fiber oscillator at about 1550 nm, amplified in Er fiber, Raman-shifted to 1800 to 2100 nm, stretched in a fiber stretcher, and amplified in Tm-doped fiber.

1 . An optical pulse source comprising:
 a fiber based laser system comprising a seed laser configured to emit optical seed pulses;   a pulse stretcher configured to stretch said seed pulses;   a Tm fiber amplifier configured to amplify said stretched optical pulses, said Tm fiber amplifier comprising at least one doped fiber containing Tm;   a pulse compressor disposed downstream from said at least one Tm fiber amplifier and arranged to compress pulses produced by said Tm fiber amplifier; and   an output port configured to output optical pulses compressed with said pulse compressor.   
     
     
         2 . The optical pulse source according to  claim 1 , wherein said seed laser comprises an Er laser. 
     
     
         3 . The optical pulse source according to  claim 1 , wherein said seed laser comprises a mode-locked Er fiber oscillator. 
     
     
         4 . The optical pulse source according to  claim 3 , wherein said fiber based laser system comprises a Raman shifter configured to generate Raman scattering within said fiber based laser system to shift a wavelength of a pulse generated with said mode-locked Er fiber oscillator to a longer wavelength in a range extending from about 1600 nm to about 2200 nanometers. 
     
     
         5 . The optical pulse source according to  claim 1 , wherein said output optical pulses have wavelengths in a range from about 1600 nm to about 2200 nm and at least partially overlap with wavelengths of a Tm or Ho fiber gain spectrum. 
     
     
         6 . The optical pulse source according to  claim 1 , wherein said Tm fiber amplifier operates at a laser wavelength of about 2 μm and has a gain-bandwidth of about 100 nm to 300 nm. 
     
     
         7 . The optical pulse source according to  claim 1 , wherein said fiber based laser system is configured to generate frequency components via spectral broadening, said frequency components at least partially overlapping with a Tm or Ho fiber gain spectrum. 
     
     
         8 . The optical pulse source according to  claim 1 , further comprising one or more nonlinear crystals for frequency conversion. 
     
     
         9 . The optical pulse source according to  claim 8 , wherein said frequency conversion comprises frequency doubling. 
     
     
         10 . The optical pulse source according to  claim 8 , wherein said one or more nonlinear crystals comprise periodically poled lithium-niobate, periodically poled KTP, periodically-twinned Quartz, periodically poled RTA, periodically poled lithium tantalate, periodically poled potassium niobate, or orientation patterned GaAs. 
     
     
         11 . The optical pulse source according to  claim 1 , wherein said pulse compressor comprises a bulk grating compressor, a Bragg grating compressor, a large mode fiber, or a photonic crystal fiber compressor. 
     
     
         12 . The optical pulse source according to  claim 1 , wherein said pulse compressor comprises a first nonlinear crystal, said first nonlinear crystal being periodically poled and chirped so as to substantially frequency double the optical pulses amplified by said Tm fiber amplifier. 
     
     
         13 . The optical pulse source according to  claim 1 , wherein said Tm fiber amplifier is core pumped or cladding pumped. 
     
     
         14 . An optical pulse source comprising:
 a fiber based laser system comprising a seed laser configured to emit optical seed pulses, said seed pulses emitted at a laser wavelength of about 2 μm;   a pulse stretcher configured to stretch said optical seed pulses;   a fiber amplifier configured to amplify said stretched optical seed pulses;   a pulse compressor disposed downstream from said fiber amplifier and arranged to compress pulses produced by said fiber amplifier; and   an output port configured to output optical pulses compressed with said pulse compressor,   wherein said optical pulses output from said output port have a pulse width of about 1 nanosecond or less and have an output wavelength extending from about 1800 nanometers to about 2100 nanometers.   
     
     
         15 . The optical pulse source according to  claim 14 , wherein said fiber amplifier comprises at least one fiber doped with Tm. 
     
     
         16 . The optical pulse source according to  claim 14 , wherein said fiber amplifier comprises at least one fiber doped with Ho. 
     
     
         17 . (canceled) 
     
     
         18 . (canceled) 
     
     
         19 . (canceled) 
     
     
         20 . (canceled) 
     
     
         21 . (canceled) 
     
     
         22 . (canceled) 
     
     
         23 . An optical pulse source comprising:
 a fiber based laser system comprising a seed laser configured to emit optical seed pulses;   a positive dispersion pulse stretcher configured to stretch said seed pulses;   a Tm fiber amplifier configured to amplify said stretched optical pulses, said Tm fiber amplifier comprising at least one doped fiber containing Tm;   a dispersive pulse compressor arranged to compress pulses amplified by said Tm fiber amplifier,
 wherein said dispersive pulse compressor is configured to produce negative dispersion, and 
 wherein said dispersive pulse compression occurs in either the Tm fiber amplifier or an additional negative dispersion fiber located downstream of said Tm fiber amplifier; and 
   an output port configured to output optical pulses compressed with said dispersive pulse compressor.   
     
     
         24 . The optical pulse source according to  claim 23 , further comprising an optical modulator configured as a pulse picker, said modulator disposed downstream from said seed laser.