| 摘要 |
PURPOSE:To remove the necessity of synchronizing right and left irradiating lights with each other and increase a duty ratio by modulating the irradiating lights from right and left lamps by different frequencies and wavelengths and conducting a concurrent irradiation. CONSTITUTION:Irradiating lights from lamps 2a, 2b, 2c and 2d are made intermit tent at frequencies fa, fb, fc and fd and wavelengths lambdaa, lambdab, lambdac and lambdad, respective ly. Lights whose intensities are modulated are irradiated on an optical fiber 1 from the side of the lamps 2a and 2b and the side of the lamps 2c and 2d and mean light intensities in the fiber 1 when the lights are transmitted to integrating spheres 4 and 5 are detected by photoelectrically converting elements 6 and 7 to be amplified (8, 9), respectively. Then, the outputs of amplifiers 8 and 9 are inputted to band-pass filters 10a-10d and 11a-11d, respectively. Arithmetic means 14 calculates the effective values of signals obtained by trans mitting the outputs of the amplifiers 8 and 9 through the filters 10a-10d and 11a-11d and optical transmission losses K1 and K2 are obtained, respectively. |
