A UV laser source for biological and chemical sensing

• Optical parametric oscillator (OPO) and sum-frequency mixing (SFM) devices are useful tools for constructing ultraviolet (UV) laser sources for fluorescence spectroscopy. Here, a compact UV-laser sources based on frequency conversion of an actively Q-switched Nd:YAG laser is presented. The second harmonic generation from a Nd:YAG laser was utilized as pump radiation for a periodically poled KTiOPO4 nanosecond optical parametric oscillator(1). The OPO-signal and the remaining pump were spatially mode-matched for Type I SFM in a beta-barium borate (BBO) crystal and UV radiation at 293 nm could be generated. This corresponds to a conversion efficiency of 2% with respect to the 532 nm harmonic radiation. The wavelength region accessible with this UV source is useful for chemical and biological sensing. Excitation of tryptophan at 293 nm for detection of fluorescence emission in ovalbumin and transthyretin was demonstrated.

Subject headings

NATURVETENSKAP  -- Fysik -- Atom- och molekylfysik och optik (hsv//swe)

NATURAL SCIENCES  -- Physical Sciences -- Atom and Molecular Physics and Optics (hsv//eng)

Keyword

ultraviolet laser source

optical parametric oscillator

sum-frequency mixing

chemical sensing

biological sensing

NATURAL SCIENCES

Publication and Content Type

ref (subject category)

kon (subject category)