| 摘要 |
PURPOSE:To realize high resolution and high response by detecting the light discharged from an optical waveguide of amplifying medium to the outside and passed through a slit and then determining a noise factor F from a value PSE thus detected. CONSTITUTION:A slit 2 having a width wide for the signal light input end of an amplifying medium 1 but narrow for the signal light output end thereof is provided in the vicinity of the amplifying medium 1. The light emitted spontaneously from the amplifying medium 1 is weighted and the light passed through the slit 2 is detected and then a noise factor F is operated according to a formula; F=2RN2eff/[(1+R)N2eff-1], where R=Oemi/Oabs, N2effidenticalPSE/PSEO, Oemi represents an inductive emission cross-sectional area at the wavelength of signal light, Oabs represents an absorptive cross-sectional area at the wavelength of signal light, N2eff represents an effective occupancy at higher level, PSE represents a measurement of spontaneously emitted light, PSEO represents a saturable value of the spontaneously emitted light at the time of N2eff=1. |
