Recent developments in laser technology make accessible a wide variety of laser spectrometers applications. Raman spectroscopy has been reactivated by the use of high-technology laser systems in the visible spectrum.
The term spectroscopy identifies methods where the interaction of light with matter is used. Optical spectrum plays a meaningful role and the strength of interaction is measured as a function of the wavelength or optical frequency.
Many of the modern spectroscopic methods include one or several lasers and are then called laser spectroscopy. Because of the great potentials of lasers in terms of temporal and spatial coherence, narrow linewidth and wavelength tunability, optical power, ultrashort pulse generation etc., the field of spectroscopy has been widened very significantly ever since the advent of lasers.
Due to the wide range of methods for laser spectroscopy, there is also a broad range of different laser spectrometers which are used for such purposes:
- Small single-frequency laser diodes can be used as inexpensive and compact wavelength-tunable sources. The emission wavelength is often tuned just by varying the drive current, which influences on the temperature.
- A frequency tuning laser (tunable laser) is a laser the output wavelength of which can be tuned (i.e. adjusted). Sometimes, the especially wide tuning range is desired, i.e. a wide range of accessible wavelengths, whereas in other cases it is sufficient that the laser wavelength can be tuned to a certain value. Frequency tuning lasers are sometimes called wavelength agile or frequency agile when the tuning can be done with high speed.
- Intracavity frequency laser serves an optical cavity (usually resonant with one or more of the wavelengths of radiation used to observe absorption) to enhance the sensitivity. It is based on frequency doubling, similar to other processes of nonlinear frequency conversion, can have a high power conversion efficiency only if sufficiently high optical intensities are reached in the nonlinear crystal material. This is often not possible for low- or moderate-power continuous-wave lasers. A good solution in such cases – is the our green fiber laser based on our fiber optical technology, a proprietary technology for intracavity doubling of the unpolarised Yb Doped fiber laser with the linearly polarized green output (patent pending).