The Laser Diode, SOA, and Photonic Integrated Circuit (PIC) Simulator
Balanced detector
Balanced photo-detector and photodiodes
Constructing and attaching arbitrary LCR networks to active sections.
Simulation with PICWave software. In PICWave, arbitrary LCR networks can be constructed and attached to active sections. This example shows a balanced photo-detector, which measures the difference (in the form of an RF output voltage) between two optical input signals.
The balanced photo-detector circuit, shown below, consists of two photo-diodes coupled together with an electrical network, which acts to amplify the difference between the electrical responses of the photo-diodes, but not the particular responses of each. A constant bias is applied across the two photo-diodes using two voltage drives and the RF output voltage is measured using a current drive (injecting 0 Amps) which has a built-in voltage instrument.
The figure below shows the DC and AC response of the balanced photo-detector.
You can see below a new circuit in which the balanced photo-detector is used to drive an optical modulator, in which a CW signal is injected.
You can see below the juxtaposition of the evolution with time of the difference in optical power between the two photo-diodes and of the output power of the modulator. You can observe how the signals are matched.
