| 摘要 |
PURPOSE:To eliminate the need for any photo branching element such as light diffraction grating and achieve the improvement in reliability and maintenance by extracting the incident light components on a plurality of individual every photo detecting area of mutually different spectral sensitivity characteristics as the electric signals proportional to the respective wavelength components intensities. CONSTITUTION:The electrodes 7 of the semiconductor photo detector 9 having the two photo detecting areas consisting of P-type semiconductor layers 1, 5, N-type semiconductor layer 3 and I-type semiconductor layers 2, 4 are maintained at a constant potential and its electrodes 6 and 8 are maintained at pontentials respectively higher than that of the electrodes 7, as a result of which this semicondocutor photo detector functions as a photo diode capable of detecting the electric signals respectively independently from the two photo detecting area, whereby the respective intensiteis of the respective wavelength components lambda1, lambda2 of the photo signals may be converted to respectively independent electric signals and are thus detected without using any photo branching element such as light diffraction grating. |
