| 摘要 |
PURPOSE:To control the interference condition of outgoing light, by providing thin film waveguides which split incident light into two parts and propagate them and have a double layered structure, applying a voltage to at least one layer which is a transparent piezoelectric body, thereby generating the difference in the light paths in both waveguides. CONSTITUTION:On a transparent substrate 1, the waveguides 3a and 3b comprising a thin transparent piezoelectric film are provided through NESA films 2a- 2c and half mirrors 4a and 4b. The incident light 6 is split into two parts by the mirror 4a. One beem repeats the total reflections in the waveguide 3b and transmits through the mirror 4b. The other beam repeats the total reflection in the waveguide 3a and is reflected by the mirror 4b. Both are interfered and the light 9 is outputted. The geometrical difference in light paths is generated by applying the voltage to the transparent piezoelectric body of the waveguide 3b. Therefore monochromatic light having an arbitrary wave-length can be obtained by the light having broad spectrum width by the voltage of several tens of volts, and a variable wavelength bandpass filter function can be implemented. |
