Optical Chopper


Replacable discs
Wide & extendable frequency range


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.


Specifications :


Five slot  :  10Hz to 400 Hz

Thirty slot  :  50Hz to 3.7 kHz

Ninety Slot  :  200Hz to 11 kHz

    Chopper wheel diameter  :  105 mm

    Stability  :  +/- 1 Hz

    Frequency read out  :  16 X 1 line LCD

Reference pick-up  :  IR LED and photo transistor pair

Motor cable length  :  2 m

Operating temperature  :  10 – 50ºC

Power input  :  230V, 50Hz