External Cavity Laser Based on a Microsystem
Laser diodes emitting in the red spectral range with a small spectral line width as excitation light sources for Raman spectroscopy for quality food control of meat – BMBF project FreshScan
Functional principle
A broad area or tapered laser diode is mounted on a micro-optical bench. The rear facet of this device is anti-reflection coated. On the back side a fast axis and slow axis collimator directs the beam to a reflecting Bragg grating (RBG). This RBG stabilizes the emission wavelength and its spectral width of typically 100 pm.
- Microsystem light source at 670 nm
Applications
- Excitation light source for Raman spectroscopy
- Pump source for the non-linear frequency conversion
- Various sensor applications
Wavelength
- 670 nm
- 650 nm
Technology and Mounting
- Semiconductor structures with MOVPE
- Chip technology:
- Broad area and tapered diode lasers with anti reflection coated rear facets
- Active alignments on a micro-optical bench
Typical data
- Broad area devices with a stripe width of 100 µm reaching an output power of 1.5 W at 671 nm [Publication, Maiwald 2008]
- Spectral line width smaller than 100 pm (95% of the power)
- Compact module