| 摘要 |
PURPOSE:To improve the property at the low frequency with no increment of the noise of low frequency and no deterioration of the differential phase, by constituting the circuit in such a way that the feedback quantity is increased at the low frequency and decreased at the high frequecny respectively. CONSTITUTION:Curve mu and beta display by the broken lines the approximate equations which are applied to secure a large amount of the feedback at the low frequncy (f2>f1). The gain of addition amplifiers 1-6 and 16 is decided by the sum of the resistance value of resistance R2 and 3 plus the resistance value ratio of R1 at an extremely low frequency, and then decided with the ratio between R2 and 1 at a sufficiently high freqiency. In short, the property of mu is realized. At the same time, luminous element 8 is delivered to optical fiber 9, and also part of the luminous element is fed back via optical fiber 10 and converted (11) to the electric signal to be then applied to BETA formation circuits 13-15 via preamplifier 12. These circuits transmit directly the signal to addition resistor 16 at a sufficiently low frequency, but have no further reduction at frequency f2 or more due to the ruling effect of resistor 15. Thus, the property of BETA is achieved. |
