Tandem OPO systems for mid-infrared generation using quasi phase-matching and volume Bragg gratings
2007 (English)In: Proceedings of SPIE - The International Society for Optical Engineering, SPIE - International Society for Optical Engineering, 2007, Vol. 6738, 73805-73805 p.Conference paper (Refereed)
Efficient laser sources in the 3 - 5 μm wavelength range are needed for directed infrared countermeasures, but also have applications in remote sensing, medicine and spectroscopy. We present results and discuss the possibilities of a tandem optical parametric oscillator (OPO) scheme for converting the radiation from a 1.06 μm Nd3+-laser to the mid-infrared. Our setup uses type I quasi phase-matched (QPM) crystals in a near degenerate OPO to generate 2.13 μm radiation. The QPM crystal provides higher nonlinearity and longer interaction lengths, because walk-off is avoided, compared to conventional bulk crystals. This is an advantage especially in low pulse energy applications. To make the 2.13 μm radiation usable for pumping a second OPO a volume Bragg grating is used as a cavity mirror to limit the bandwidth, which in a conventional QPM OPO at degeneracy can be several hundred nanometers. The acceptance bandwidth for efficient OPO operation of a 14 mm long ZnGeP2 (ZGP) crystal is approximately 5 nm, which makes the need for bandwidth limiting clear. The majority of the signal energy from a periodically poled KTiOPO4 (PP KTP) OPO with a volume Bragg grating output coupler was found to be in a single longitudinal mode, whereas the idler bandwidth was measured to 19 GHz (FWHM). A volume Bragg grating resonant near 2124 nm was chosen so that the signal and idler were separated by 9 nm. This OPO output has been used as a pump source for a conventional ZGP OPO demonstrating efficient conversion and providing broadband tunable output in the mid-infrared.
Place, publisher, year, edition, pages
SPIE - International Society for Optical Engineering, 2007. Vol. 6738, 73805-73805 p.
, Proceedings of SPIE - The International Society for Optical Engineering, ISSN 0277-786X
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:kth:diva-181751DOI: 10.1117/12.737229ISI: 000252958400003ScopusID: 2-s2.0-42149105080OAI: oai:DiVA.org:kth-181751DiVA: diva2:899979
SPIE Europe Optics & Photonics in Security and Defence (ESD07), Technologies for Optical Countermeasures IV, Florence, Italy 17-20 September, 2007.
QC 201602222016-02-022016-02-022016-05-30Bibliographically approved