Split-beam Fourier filter

摘要

PCT No. PCT/AU95/00551 Sec. 371 Date May 2, 1997 Sec. 102(e) Date May 2, 1997 PCT Filed Aug. 30, 1995 PCT Pub. No. WO96/07114 PCT Pub. Date Mar. 7, 1996An optical filter, comprising a first optical waveguide, a second optical waveguide and means for expanding light from the first optical waveguide into a beam, and at least one optical flat inserted partially into the beam so that a fraction of the light passes through each optical flat and a means for focussing the light into the second optical waveguide. In its simplest form the device has a Mach-Zehnder (sinusoidal) transmission characteristic. The filter can be tuned both in wavelength and extinction either mechanically or electrically. More complex (non-sinusoidal) characteristic can also be obtained.