Chirped quasi phase-matched optical parametric amplifier/difference frequency generator (CQPM OPA/DFG)-based optical tuning method, apparatus, and applications

A method for tunable wavelength selection in a broadband laser output, comprising:

• generating a pump pulse having a fixed wavelength, a center optical frequency, and a pulse duration (λp, υp, τp) and propagating the pump pulse along a pump pulse optical path;
• generating a seed pulse having a wavelength, frequency, and pulse duration (λs, υs, τs) and propagating the seed pulse along a seed pulse optical path, wherein τp<<τs;
• amplifying the pump pulse to a sufficient peak power;
• spectrally broadening and chirping the seed pulse to generate a chirped, seed pulse spectrum;
• collinearly combining the amplified pump pulse and the chirped, seed pulse spectrum, wherein the pump pulse optical path and the seed pulse optical path are matched up to the point of combination;
• inputting the collinearly combined amplified pump pulse and the chirped, seed pulse spectrum into a chirped quasi phase-matched optical parametric amplifier/difference frequency generator (CQPM OPA/DFG) including a CQPM non-linear medium having a length and a chirp period, wherein the chirped, seed pulse spectrum is substantially matched to the length and the chirp period of the CQPM non-linear medium;
• and
• non-mechanically adjusting a time delay between the pump pulse and the seed pulse to select a particular phase-matched spectral bandwidth overlap region between the amplified pump pulse and the chirped, seed pulse spectrum in the CQPM non-linear medium, thus providing a discrete, tunable output wavelength over the seed pulse spectrum.