Dual-crystal OPO enables generation of multiple arbitrary wavelengths

In January 2011, Laser Focus World reported on a multicrystal scheme for 56% efficient second-harmonic generation (SHG) of near-infrared light at 1064 nm to green light at 532 nm. Now, that same team of researchers from the Institute of Photonic Sciences (ICFO) and the Catalan Institute of Research and Advanced Studies (ICREA), both in Barcelona, Spain, have developed a multicrystal optical parametric oscillator (OPO) that can provide two arbitrary, independently tunable pairs of signal and idler wavelengths.
In conventional OPOs, although the output signal and idler frequencies ω1 and ω2 can be varied, they are always linked to one another through energy conservation and phase-matching conditions and cannot be independently tuned. This has been a fundamental limitation of OPOs since they were first demonstrated nearly 50 years ago. The researchers overcame this fundamental limitation using two nonlinear crystals inside a single OPO cavity. Using this new technique, it is possible to produce two frequencies (ω1, ω1’) from the two crystals that are almost identical (as close as 0.55 THz). Because the device can provide completely independent tuning of frequency pairs (ω1, ω2) and (ω1’, ω2’), it can provide any combination of the four frequencies, and therefore truly arbitrary tuning.
Contact Goutam Samanta at [email protected].

Gail Overton | Senior Editor (2004-2020)
Gail has more than 30 years of engineering, marketing, product management, and editorial experience in the photonics and optical communications industry. Before joining the staff at Laser Focus World in 2004, she held many product management and product marketing roles in the fiber-optics industry, most notably at Hughes (El Segundo, CA), GTE Labs (Waltham, MA), Corning (Corning, NY), Photon Kinetics (Beaverton, OR), and Newport Corporation (Irvine, CA). During her marketing career, Gail published articles in WDM Solutions and Sensors magazine and traveled internationally to conduct product and sales training. Gail received her BS degree in physics, with an emphasis in optics, from San Diego State University in San Diego, CA in May 1986.