| 摘要 |
<p>PURPOSE:To realize a stable inverting type amplifier by allowing a photoelectric conversion element to convert the received input light into a photovolatile current and allowing a drive means to drive an electrooptic conversion element by a current inversely proportional to the said photovolatile current. CONSTITUTION:Let an input light be P1, let a reference input light be PREF, then the input lights P1, PREF are converted respectively into photovolatile currents IP2, IP1 by two photodiodes (photoelectric conversion elements) PD2, PD1. An amplifier A amplifies the difference between the photovolatile currents IP1, IP2 to supply the forward current IF of a laser diode (electrooptic conversion element) LD. Thus, the laser diode LD generates a light output P0. A light kP0 proportional to the output light P0 from the laser diode LD is fed back to the photodiode PD2. When the input light P1 is close to the reference input light PREF, the output light P0 is linear as shown in figure. The gradient in this case is (1/k), which represents the amplification factor. The transfer characteristic of the input/output light is represented as the inverting amplification.</p> |
