OPO Spectrometer
In a collaboration with Prof. Goeff
Blake we demonstrated the use of a continuously tunable laser spectrometer
using optical parametric oscillator technology for mineral spectroscopic
applications. Postdoc Zifu Wang
collaborated with Blake's group which developed the basic laser technology.
Our new spectrometer was based on a single pump laser tuned with optical
parametric oscillator crystals (OPOs). It allows the pump laser to
be tuned over a broad wavelength range. Our system is pumped at either
355 (for visible operation) or 532 nm (for NIR operation). The OPOs
are based on type II phase matching in b-BaB2O4
(BBO). These instruments have an immensely more intense output compared
to the conventional instruments we now use. To test the feasibility
of characterizing extremely small samples, we conducted absorption spectral
measurements in the near-IR wavelength range on several single-crystal
samples masked with pinholes of diameter 5 to 12.5 mm. Our prototype
unit operated from about 410 to 3300 nm.
The OPO spectrometer |
More information and images on the
OPO spectrometer