Seiichi KAKUMA^* and Ryoji OHBA

Division of Applied Physics, Graduate School of Engineering, Hokkaido University, Kita-13, Nishi-8, Kita-ku, Sapporo 060-8628, Japan

(Received July 28, 2003; Accepted September 25, 2003)

A self-mixing type range finder is proposed using the polarization self modulation phenomenon of a vertical-cavity surface-emitting laser diode, in which the polarization mode switches between two inherent modes of the laser diode. The length to be measured is determined from the switching frequency, the accuracy of which is quite excellent with a relative error of less than 10 ppm. Experimental results prove that the present method is feasible as a practical and highly accurate ranging technique.

Key words: VCSEL, length measurement, polarization self modulation, switching, frequency, quarter wave plate

^*E-mail address: kakuma@eng.hokudai.ac.jp