CH-30 Low Frequency Large Aperture Resonant Chopper

CH-30 Low Frequency Large Aperture Resonant Chopper Description:

Datasheet

The CH-30 resonant chopper / optical modulator is a low frequency chopper. This is a ONE FIXED FREQUENCY electromechanical driven device with a blade which reflects or blocks a light beam with a sinusoidal motion.

The CH-30 chopper is used to chop a large diameter beam at a low frequency or for sequentially chopping a pair of parallel beams or a bundle of beams. Another important use of the chopper is in detection applications, where optical signals are obscured by noise. A fixed frequency modulated signal can be filtered from background noise. This is best achieved using a lock-in amplifier. The detected signal and the reference signal (mixed with the frequency of the chopper) cause the frequency of interest to appear as a pure dc output level. All other signals are filtered with the low pass filter. Once noise is removed, proper signal measurements can be obtained.

The CH-30 chopper can be used in ultra high vacuum, high temperature and in cryogenic environment. A chopper that meets MILITARY SPECIFICATIONS is available as a special order. A dark blade is or a bright blade is standard. A mirror epoxied on the blade turns the device to a CHOPPER FOR HIGH POWER. A special blade configuration is available as a special order.

Drive electronics with a different package, regulation and power supply options is available as a special order. Special pricing is available for OEM applications.

The ED driver and the AGC driver are both oscillators using the chopper as a frequency source. The AGC driver also provides a high amplitude stability (0.005%) and both sine wave and TTL reference signals. The PLD-1C driver phase locks a chopper to an external clock signal. The PLD-2C driver phase locks two choppers in a "master/slave" chopping system.

Features and Advantages:

The following should serve as guide lines only:

ORDERING INFORMATION

TYPE [CH-30]; VANE [B=bright or D=dark]; FREQUENCY [Hz]; VANE SIZE [W,L]; ANGULAR MOTION [P-P Deg.]

Example: PART NO. CH30-D-200-1×1.5-30. This part number specifies the model CH-30 chopper, dark vanes and a 200 Hz operating frequency, 1 inch vane width × 1.5 inch vane length and 30° peak to peak angular motion.

Drive electronics with different packages, regulation, and reference signal and power supply options are available. Special pricing for OEM applications.