Tailored UV-laser source for fluorescence spectroscopy of biomolecules
2007 (English)In: Optics and lasers in engineering, ISSN 0143-8166, E-ISSN 1873-0302, Vol. 45, no 4, 444-449 p.Article in journal (Refereed) Published
A dual-wavelength UV-laser source was developed for biosensing. First, a passively Q-switched diode-pumped Nd:YAG laser was constructed. The astigmatic diode output beam was converted into a homogenous beam profile by utilizing a mode converter. As a result, a frequency-doubling conversion efficiency of 50% was achieved in a periodically poled KTiOPO4. With a repetition rate of 100 Hz, the pulse energies and lengths were 650 mu J and 1.8 ns, respectively, at 532 nm with a M-2 of 1.3. The UV-generation is based on cascaded parametric processes using an intra-cavity sum-frequency mixing scheme in a periodically poled KTiOPO4 parametric oscillator pumped at 532 nm. Here, the wavelengths 293 and 343 nm were generated, with conversion efficiencies of 7% and 6.5%, respectively, in respect to 532 nm. With pulse length 1 ns and an average power above 2.7 mW, the wavelengths were used for fluorescence measurements of nonpathogenic bacteria.
Place, publisher, year, edition, pages
2007. Vol. 45, no 4, 444-449 p.
diode pump solid-state laser, beam transformation, beam shaping, optical parametric oscillator, parametric devices, ultraviolet generation
Atom and Molecular Physics and Optics
IdentifiersURN: urn:nbn:se:kth:diva-5903DOI: 10.1016/j.optlaseng.2005.03.016ISI: 000245108800002OAI: oai:DiVA.org:kth-5903DiVA: diva2:10433
QC 201009232006-06-012006-06-012015-03-30Bibliographically approved