Diode laser based light sources with an emission in the blue spectral range are developed for generating UV laser emission by nonlinear frequency conversion. Potential applications are Raman spectroscopy, utilizing the spectral separation of Raman signals from disturbing contributions such as fluorescence at longer wavelengths, and absorption spectroscopy.
Commercially available GaN based diode lasers at around 450 nm are externally wavelength stabilized by external transmitting volume Bragg gratings. Subsequent single-pass nonlinear frequency conversion of such light sources is applied to generate UV laser emission available for corresponding applications such as Raman spectroscopy.
- Excitation light sources for Raman spectroscopy and absorption spectroscopy
- 450 nm (external cavity diode laser)
- 225 nm (UV generation)
- In-house developed packaging
- Active alignment and mounting of optical components for wavelength-stabilized laser emission
- Non-linear frequency conversion in single-pass configurations
- 1.4 W at 445 nm by external cavity GaN-based diode laser
- 160 µW by single-pass nonlinear frequency conversion GaN diode laser
The development of the diode lasers was funded by the Einstein Foundation Berlin in the project HautScan (Duration: 01.08.2012 - 31.07.2015).