Michelson interferometer including a non-polarizing beam splitter

摘要

PCT No. PCT/JP94/01905 Sec. 371 Date Jul. 14, 1995 Sec. 102(e) Date Jul. 14, 1995 PCT Filed Nov. 11, 1994A light power spectrum is accurately measured, in spite of the polarized light-dependency of the non-polarizing beam splitter 12. Incident light 11 is separated by a polarizing/separating element 31 into orthogonal polarized light components 11a and 11b. The orthogonal polarized light components have their polarizing directions rotated by 45 degrees in opposite directions with respect to their P wave components and S wave components at the reflecting/transmitting face of the non-polarizing beam splitter. The reflected and transmitted from the non-polarizing beam splitter 12 are reflected by a stationary reflector 16 and a moving reflector 17 back to the non-polarizing beam splitter 12 and are recombined to interfere with each other at the reflecting/transmitting face of the non-polarizing beam splitter. The resulting interference lights are received by a common light-receiver.