Optical Chopper
These high stability variable frequency optical choppers each include a set of chemically blackened photoetched chopping discs. The mini chopper is an excellent choice for applications requiring a compact package. The chopping discs come in a variety of slot apertures and allow operation. Beam diameter is limited to 0.75mm when using the 200-slot disc and 1.0mm when using the 40 slot mini disc. The easy-to-interchange blades are made of non-magnetic, half hard brass and can be used in combination. Chopping frequency is set by adjusting a ten-turn dial or by applying an external DC voltage to the BNC input. Reference output is a TTL pulse and is in-phase with chopping action. The 5 digit led display gives a direct read-out of the chopping frequency. Power: 90-130V or 180-260V; 50/60Hz; 12VA max. Power supply included. Choppers are often used together with lock-in amplifiers.
