Videreutvikling system for posisjonering/DP - test av prototyp system med øyesikker 1550 nm laser diode/fiber laser teknologi

Abstract

This master work deals with investigating a laser based range finding system. The laser has a wavelength of 1 550 nm and the system will be comparable to SpotTrack, which uses 905 nm. This paper will build on the work that was done in the autumn of 2016, where investigations were carried out to find out which lens would be the best option to use together with a diode laser, an acylindrical or a cylindrical lens \cite{prosjekt}. The conclusion there was that the acylindrical lens would be the better option. That solution has been incorporated in to this work.

This work has focused on what combinations of laser and detector would be the best option do develop further, if that even is a good option. This has been based on eye safety evaluations, costs of laser and detector compared to the those of SpotTrack and how well the system performs compared to SpotTrack. Two kinds of lasers were considered, fiberlaser and diode laser. Fiber lasers will be able to send out higher power and a more narrow beam, but are very costly. Diode laser are cheaper, but have a larger beam divergence, which will reduce the range. The detectors that were looked into were pin detector and avalanche photodiode (APD). Here too, the choice was between costs and performance. Pin detectors are generally less sensitive, but cheap compared to APDs. APDs have high sensitivity, but will easily become expensive.

These factors were weighed against each other and compared. The finding was that a combination consisting of a laser diode and an APD would be the best option to develop further seeing that the range would be good and the increase in costs moderate. Furthermore, a laser system with a laser diode giving out strength would be more eye-safe than a fiber laser on full strength.