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.
The following should serve as guide lines only:
FREQUENCY
(Hz) |
ANGULAR MOTION
(P-P Degrees) (at top of vane) |
W (width)
(Inches) |
L (length)
(Inches) |
D (beam dia.)
(Inches) |
6.5 |
30 |
1.00 |
1.50 |
0.60 |
13 |
30 |
1.00 |
1.50 |
0.60 |
25 |
30 |
0.78 |
1.25 |
0.60 |
40 |
25 |
0.78 |
1.00 |
0.40 |
100 |
15 |
0.30 |
0.40 |
0.30 |
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.
