Can I use a Model 410X amplitude modulator as an optical switch or for optical chopping?
Yes, the Models 4103 and 4104 amplitude modulators can be used as optical switches or for optical chopping. For a 1-mm diameter beam these devices have typical on:off extinction ratios of 50:1 or greater. The Model 4104 is a broadband modulator that can be operated over a wide frequency range. This device requires about 450 volts to turn 1.6 µm light on and off. Our Model 3211 high-voltage amplifier can be used to drive the Model 4104. However, the 3211 only operates from DC to 600 kHz, and the maximum output voltage is +200 to -200 volts. For higher frequencies you can use the Model 4103, which is a resonant amplitude modulator. The 4103 requires a much lower drive voltage, but since it uses a resonant circuit, the 4103 can only be operated at one customer-specified frequency from 10 kHz to 200 MHz. By chopping at these higher frequencies far away from the 1/f noise, you can achieve shot-noise-limited detection.
