An optical frequency comb generation system includes an optical waveguide portion having a uniform width, a first chirped Bragg grating disposed at one end of the optical waveguide portion and a second chirped Bragg grating disposed at the other end of the optical waveguide portion. The first chirped Bragg grating includes at least a first periodic variation having a first refractive index and a second periodic variation having a second refractive index. The second chirped Bragg grating includes the at least first and second periodic variations. A first cavity associated with a first resonant frequency extends between the first periodic variation of the first chirped Bragg grating and the first periodic variation of the second chirped Bragg grating. A second cavity associated with a second resonant frequency extends between the second periodic variation of the first chirped Bragg grating and the second periodic variation of the second chirped Bragg grating.

An optically nonlinear crystal is arranged for frequency-doubling an input pulse. The crystal has parallel facets each coated with a reflective coating. The crystal is arranged with respect to the input pulse such that the input pulse makes a plurality of forward and reverse passes between the coatings. A frequency-doubled pulse is generated on the forward passes. The input pulse and the frequency-doubled pulse propagate with different group velocities in the crystal such that temporal separation the pulses occurs. The crystal and reflective coatings are configured such that the temporal separation does not exceed a predetermined value.

A frequency-doubled laser, including: a first reflecting mirror, a second reflecting mirror, a gain medium, a telescope module, a polarizing element, and a nonlinear crystal; the first reflecting mirror and the second reflecting mirror are spaced apart to form a resonator of the frequency-doubled laser; the polarizing element, the gain medium, the telescope module, and the nonlinear crystal are located in the resonator, and the telescope module is located between the gain medium and the nonlinear crystal. The present disclosure further provides a method of generating harmonic laser. The frequency-doubled laser and the method of generating harmonic laser make the position of nonlinear crystal more flexible, and the possibility of damage to the nonlinear crystal is reduced.

An optical frequency comb generation system includes an optical waveguide portion having a uniform width, a first chirped Bragg grating disposed at one end of the optical waveguide portion and a second chirped Bragg grating disposed at the other end of the optical waveguide portion. The first chirped Bragg grating includes at least a first periodic variation having a first refractive index and a second periodic variation having a second refractive index. The second chirped Bragg grating includes the at least first and second periodic variations. A first cavity associated with a first resonant frequency extends between the first periodic variation of the first chirped Bragg grating and the first periodic variation of the second chirped Bragg grating. A second cavity associated with a second resonant frequency extends between the second periodic variation of the first chirped Bragg grating and the second periodic variation of the second chirped Bragg grating.

Systems and methods for spectrally broadening seed pulses with a single pass laser amplifier are disclosed. A bulk TM:II-VI polycrystalline material with combined gain and nonlinear characteristic provides passive (cold) spectral broadening of high power seed pulses. Continuous pumping provides more significant spectral broadening. In particular, pulsed pumping of TM:II-VI polycrystalline material (e.g. Cr2+:ZnS, Cr2+:ZnSe, and Cr2+:CdSe) is shown to provide significant spectral broadening to the super continuum generation SCG level. Pulse picking, pump sources, master oscillators and various optical components are described.

An optically nonlinear crystal is arranged for frequency-doubling an input pulse. The crystal has parallel facets each coated with a reflective coating. The crystal is arranged with respect to the input pulse such that the input pulse makes a plurality of forward and reverse passes between the coatings. A frequency-doubled pulse is generated on the forward passes. The input pulse and the frequency-doubled pulse propagate with different group velocities in the crystal such that temporal separation the pulses occurs. The crystal and reflective coatings are configured such that the temporal separation does not exceed a predetermined value.

A system is provided for generating a laser beam via non-linear effects, including: a monofrequency continuous-wave laser source; and an external resonant cavity referred to as a microchip cavity. The microchip cavity is composite insofar as it is a unitary assembly of a plurality of materials g: at least one nonlinear crystal; an entrance mirror; a concave mirror deposited on a material fixed to the nonlinear crystalthe material on which the concave mirror is deposited is different from the constituent material of the nonlinear crystal; a first thermoelectric module for controlling the temperature of the nonlinear crystal; and at least one second thermoelectric module for controlling at least the temperature of the material on which the concave mirror is deposited.

The present invention provides systems and methods for producing short laser pulses that are amplified and spectrally broadened in a bulk gain media. The bulk material, having laser gain and nonlinear properties, is concurrently exposed to an optical pump input and a seed input, the pump power being sufficient to amplify and spectrally broaden the seed pulse.

An apparatus for frequency comb generation comprises a component of second order nonlinearity, where the component is configured to interact with a laser beam or derivatives of the laser beam and thereby generate frequencies for the frequency comb. The apparatus comprises advantageously an optical manipulator, which both comprises the component but additionally is configured to introduce the beam or its derivatives in a repetitive or resonating manner to the component. The component is e.g. a monolithic or other solid optical resonator or microresonator comprising optical crystal and having said second order nonlinearity.

A method of creating difference frequency (DF) laser pulses (1) by difference frequency generation (DFG) comprises the steps of providing ultrashort laser pulses (2) having a spectral bandwidth corresponding to a Fourier limit of below 50 fs and containing first spectral components and second spectral components having larger frequencies than the first spectral components, and driving a DFG process by the ultrashort laser pulses (2) in an optically non-linear crystal (10), wherein the DF laser pulses (1) are generated in the crystal (10) by difference frequencies between the first and second spectral components, resp., said difference frequencies comprising third spectral components being lower in frequency than the first and second spectral components, wherein at least one enhancement cavity (20) with resonator mirrors (Mi1 to M14) spanning a beam path (22) is provided and the crystal (10) is placed in the beam path (22) of the enhancement cavity (20), the ultrashort laser pulses (2) are input coupled and coherently added in the at least one enhancement cavity (20), at least one circulating ultrashort laser pulse (3) is created in the at least one enhancement cavity (20), which drives the DFG process in the crystal (10) for generating the DF laser pulses (1), and the at least one enhancement cavity (20) is adapted for recycling the at least one ultrashort laser pulse (3) passing through the crystal (10). Furthermore, a photonic source (100) for creating DF laser pulses (1) is described, including one or more enhancement cavities.