Lasers with high coherence for measuring purposes
Lasers designed at ISI are unique due to their high coherence and are suitable for:
- precision length measurements on the basis of laser interferometry;
- analysis of gases and other transparent media through laser spectroscopy.
ISI is equipped with laser sources with high coherence operating at the following wavelengths: 502 nm, 532 nm, 543 nm, 633 nm, 760 nm, 780 nm, 1064 nm, 1315 nm, 1540 nm. If required this set may be broadened to include additional wavelengths.
Examples of realized designs:
- He-Ne lasers and discharge tubes for the construction of He-Ne lasers. We designed technology for manufacturing and filling of the gas He-Ne lasers that dominate in the field of precise length measurements. These lasers are thermally stable and are suitable for operation as laser sources for measuring systems based on laser interferometry. Compared with commercial lasers our design offers fast wavelength tuning via an integrated piezoelectric transducer.
- ECL lasers for measurement and spectroscopy. Traditional He-Ne lasers operating in the visible spectral range are only tunable within a very narrow range. Laser diodes perform much broader tuning range but do not operate in a single-frequency regime and are thus not suitable for demanding applications like interferometry and spectroscopy – for example, for gas analysis. We designed semiconductor laser technology with an extended cavity, which effectively reduces the laser emission spectral profile and keeps the laser's broad spectrum of available wavelengths accessible through tuning. We achieved a compact tunable laser source suitable for spectroscopic applications with an operating wavelength given by the laser diode of choice.
- Laser systems with laser diodes VCSEL, DFB and DBR. We designed specialized electronics for controlling the wavelength of commercial laser diodes operating with a narrow emission spectral range. These are the diodes with vertical cavity VCSEL (Vertical Cavity Surface Emitting Laser), distributed optical feedback DFB (Distributed FeedBack) and wavelength selective mirrors DBR (Distributed Bragg Reflector). The emission wavelengths of these diodes are controlled by the injection current of the semiconductor and also through the operating temperature. The control electronics are equipped with a set of signal processors controlling the operating point of the laser diode.
