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 1800-2100 nm and after frequency doubling in the wavelength range of 900-1050 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 1800-2100 nm, stretched in a fiber stretcher, and amplified in Tm-doped fiber.

What is claimed is: 
     
         1 . An optical pulse source comprising:
 a fiber-based laser system generating optical pulses and comprising at least one Tm-doped fiber;   one or more nonlinear crystals disposed to receive said optical pulses, said one or more nonlinear crystals configured for frequency up-conversion or down-conversion of said optical pulses and to output frequency converted optical pulses; and   an output port that outputs said frequency converted optical pulses, wherein said frequency converted optical pulses output from said output port have a pulse width of about 1 nanosecond or less.   
     
     
         2 . The optical pulse source of  claim 1 , wherein said fiber-based laser system comprises a Tm-doped mode locked fiber oscillator, and said at least one Tm-doped fiber is arranged as a portion of said Tm-doped fiber oscillator. 
     
     
         3 . The optical pulse source of  claim 1 , wherein said fiber-based laser system comprises one or more Tm-doped fiber amplifiers, and said at least one Tm-doped fiber is arranged as a portion of said at least one Tm-doped fiber amplifier. 
     
     
         4 . The optical pulse source of  claim 1 , wherein said fiber based laser system comprises both a Tm-doped fiber oscillator and a Tm-doped fiber amplifier. 
     
     
         5 . The optical pulse source of  claim 1 , wherein said one or more nonlinear crystals are configured to produce frequency doubling, frequency tripling, or frequency quadrupling. 
     
     
         6 . The optical pulse source of  claim 1 , wherein said source is configured for difference frequency mixing. 
     
     
         7 . The optical pulse source of  claim 1 , wherein said source is configured for Raman scattering. 
     
     
         8 . The optical pulse source of  claim 1 , wherein said source is configured for anti-Stokes Raman scattering 
     
     
         9 . The optical pulse source of  claim 1 , wherein said source is configured for THz generation. 
     
     
         10 . The optical pulse source of  claim 1 , where 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 of  claim 1 , wherein said one or more nonlinear crystals are configured to produce frequency down-conversion via parametric generation or THz generation. 
     
     
         12 . An optical pulse source comprising:
 a mode locked fiber oscillator comprising a Tm-doped fiber;   a Tm fiber amplifier receiving pulses from said mode locked fiber oscillator and generating amplified pulses;   one or more nonlinear crystals disposed to receive said amplified pulses, said one or more nonlinear crystals configured for frequency up-conversion or down-conversion of said amplified pulses, said one or more nonlinear crystals generating amplified and frequency converted pulses having a pulse width of about 1 nanosecond or less.   
     
     
         13 . The optical pulse source according to  claim 12 , wherein said source is configured for nonlinear Raman scattering. 
     
     
         14 . The optical pulse source according to  claim 13 , wherein said mode locked fiber oscillator is arranged as a seed laser for said Tm fiber amplifier, and
 wherein said nonlinear Raman scattering is generated within said mode locked fiber oscillator.   
     
     
         15 . The optical pulse source of  claim 12 , where 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. 
     
     
         16 . An optical pulse source comprising:
 a mode-locked Tm-doped fiber source-configured to produce optical pulses;   one or more nonlinear crystals disposed to receive said optical pulses, said one or more nonlinear crystals configured for frequency up-conversion or down-conversion of said optical pulses; and   an output port that outputs said optical pulses, wherein said optical pulses output from said output port have a pulse width of about 1 nanosecond or less.   
     
     
         17 . The optical pulse source of  claim 16 , where 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. 
     
     
         18 . The optical pulse source of  claim 16 , wherein said one or more nonlinear crystals are configured to produce frequency down-conversion via parametric generation or THz generation. 
     
     
         19 . The optical pulse source of  claim 16 , said mode-locked Tm oscillator is being core or cladding pumped. 
     
     
         20 . An optical pulse source comprising:
 a mode-locked Tm-doped fiber source configured to produce optical pulses; and   an output port that outputs said optical pulses, wherein said optical pulses output from said output port have a pulse width of about 1 nanosecond or less,   wherein said source is configured for nonlinear Raman scattering.   
     
     
         21 . An optical pulse source comprising:
 a Tm-doped fiber; and   a highly nonlinear fiber.   
     
     
         22 . The optical pulse source of  claim 21 , further comprising a fiber amplifier. 
     
     
         23 . The optical pulse source of  claim 22 , wherein said fiber amplifier comprises a Tm-doped fiber amplifier. 
     
     
         24 . The optical pulse source of  claim 22 , further comprising:
 a nonlinear crystal configured to receive the output from said highly nonlinear fiber and said fiber amplifier, said output from said highly nonlinear fiber and said fiber amplifier overlapping in time.   
     
     
         25 . The optical pulse source of  claim 24 , wherein said nonlinear crystal comprises a quasi-phase matched crystal. 
     
     
         26 . The optical pulse source of  claim 21 , wherein said source comprises more than one highly nonlinear fiber. 
     
     
         27 . An optical pulse source comprising:
 a seed laser configured to emit optical seed pulses;   a pulse stretcher configured to stretch said seed pulses;   a Tm-doped fiber amplifier configured to amplify said stretched optical pulses; and   an output port that outputs optical pulses amplified by said Tm-doped fiber amplifier,   wherein said optical pulses output from said output port have a pulse width of about 1 nanosecond or less and have a spectral content in a wavelength range extending from about 1600 to about 2400 nanometers.   
     
     
         28 . The optical pulse source of  claim 27 , further comprising a pulse compressor configured to compress said optical pulses prior to being emitted at said output port,
 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-doped fiber amplifier,   thereby producing an output in a spectral region extending from about 800 to about 1200 nanometers.   
     
     
         29 . The optical pulse source of  claim 28 , wherein said first nonlinear crystal comprises lithium niobate. 
     
     
         30 . The optical pulse source of  claim 28 , further comprising a second nonlinear crystal disposed such that said frequency doubled optical pulses are injected into said second nonlinear crystal, thereby providing additional frequency up-conversion or frequency down-conversion. 
     
     
         31 . The optical pulse source of  claim 30 , wherein said second nonlinear crystal comprises 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. 
     
     
         32 . The optical pulse source of  claim 27 , further comprising a pulse compressor, wherein said pulse compressor comprises a bulk grating compressor, a Bragg grating compressor, a large mode fiber, or a photonic crystal fiber compressor. 
     
     
         33 . The optical pulse source of  claim 27 , further comprising:
 a nonlinear crystal configured to provide frequency doubling of said amplified pulses; and   a pulse compressor arranged to compress the frequency doubled optical pulses.   
     
     
         34 . A method of producing optical pulses, the method comprising:
 producing optical seed pulses;   stretching said seed pulses;   amplifying said stretched optical pulses using a Tm-doped fiber amplifier; and   outputting said amplified optical pulses,   wherein said optical pulses have a pulse width of about 1 nanosecond or less and have a spectral content in a wavelength range extending from about 1600 to about 2400 nanometers.