UCF researchers have developed a tunable laser with broadband coherent output spectrum within the mid-infrared (IR) range using a chirped quasi phase-matched optical parametric amplifier/difference frequency generator (CQPM OPA/DFG)-based design.
Comparatively, currently available laser sources do not possess the unique combination of the following desired attributes: high average power, high pulse energy, temporal flexibility, an integrated design (i.e., pump and seed inputs for an OPA using a single drive laser construction), as well as non-mechanical tunability. Additionally, although this type of performance can be achieved using existing solid-state based laser technology, it is usually difficult to create suitably high peak power amplification of ultrashort (<100 ps), quasi time-bandwidth limited pulses in all-fiber systems.
The innovative method developed by UCF researchers overcomes these limitations by providing fast, non-mechanical wavelength tuning over a broad or ultra-broad laser output spectrum, utilizing monolithic integration and robust packaging for demanding environments. Applications include optical countermeasures, spectroscopy, hyperspectral imaging, ultrashort pulse generation and amplification, as well as applications requiring broad and rapid spectral tunability in the mid-IR region—specifically applications that require high spectral intensity and/or high average power.
This novel system involves a non-mechanical method of changing the relative timing of a pump pulse versus the seed pulse. The temporal variation varies the spatial/temporal overlap location of the spectrally narrow pump pulse over the spectrally broad seed spectrum taking place within the CQPM nonlinear medium. The overlap position regulates the phase-matched, seed pulse portion as the signal in the OPA or the seed for DFG. Piezo-electric fiber stretchers are used to vary the relative pulse timing, thus enabling the output tuning from the OPA or DFG without using any moving parts. Fiber-coupled optical amplitude and/or phase modulators can also be included in either the pump or signal channels to provide control over the optical duty cycles as well as provide fine pulse control.
- Rapid, non-mechanical wavelength tuning
- Provides broad or ultra-broad laser output spectrum
- Monolithic integration
- Robust packaging for demanding environments and applications
- Optical countermeasures
- Hyperspectral imaging
- Ultrashort pulse generation and amplification
- Medical applications