An optical chopper is a mechanical device which physically chops a light beam into discrete light pulses. It is widely used in various optical experiments. It modulates different light sources with given frequency for their subsequent analysis.
The chopping discs come in a variety of slot apertures and can be replaced with ease.
Holmarc's optical chopper is a stable device through out the frequency range. The basic system consists of control unit, rotating head and a set of four chopper discs. A DC motor drives the rotating head in closed loop control. Chopping discs are replaceable by the user with ease. A heavy base to which the rotating assembly is fixed provides stability during operation. Optical axis height is approximately 100 mm. The required disc depending on the frequency can be fixed to the rotating head. This system provide wide range of frequencies (10Hz - 3.7kHz.) A wide selection of additional discs and accessories are available to extend the frequency range and to satisfy individual requirements. Frequency is displayed directly on the digital display of the control unit. Easy-to-interchange blades are made of corrosion protected material for durability.
|Two Slot||:||10 Hz to 200 Hz|
|Six Slot||:||100 Hz to 600 Hz|
|Thirty slot||:||200 Hz to 4000 Hz|
|Duty Cycle||:||50 %|
|Stability||:||+/- 1 Hz|
|Chopper Wheel Diameter||:||105 mm|
|Frequency Read Out||:||16 x 2 Lines LCD|
|Reference Pick-Up||:||IR LED and Photo Transistor Pair|
|Motor Cable Length||:||1.5 m|
|Operating Temperature||:||10ºC - 50ºC|
|Power input||:||230V, 50Hz|
The delay generator accepts a TTL pulse train having a frequency between 10 Hz to 4 kHz, and provides a delayed version of the same signal. The amount of time delay can be set using the front panel buttons and the LCD display. It can delay the signal by 10 microseconds minimum to 60 milliseconds maximum. This device can be used for triggering a measurement device or camera when used with an optical chopper. The reference signal from the optical chopper may not be in phase with the chopped laser output. Adding a user specified delay to the reference signal will make it in phase with the laser and bring the triggering in sync with the laser pulsations.
|Input signal||:||TTL (5V) pulses|
|Input signal frequency range||:||10 Hz to 4000 Hz|
|Minimum delay||:||10 microsecond|
|Maximum delay||:||60 millisecond|
|Delay resolution||:||1 microsecond|
|User interface||:||Alphanumeric LCD and buttons|
|Input & Output connectors||:||BNC|
|Power input||:||90 - 260V / 50 - 60Hz|
Price : $ 409