EOP-CH-30 Tuning Fork resonant Chopper

Description

Vanes attached to moving tines of a fork modulate a light beam. The chopper operates at the natural resonant frequency established by the effective mass of the moving assembly and the spring constant of the tines.

Chopping frequency ranges from 10 Hz to 6 KHz, apertures up to 15 mm are practical in the lower frequencies (under 100 Hz), 0.5 mm at 3 KHz and 0.2 mm at 6 KHz. If the beam size is limitting the chopper rate, consider focusing at the chopper to reduce the  beam size. The amplitude of the motion of the chopper is inversely proportional to its frequency. You will find examples of the frequency amplitude relationship in the table below. Dark or bright vanes are standard; mirrors, lenses or gratings optional.

Low cost, compact size, lightweight and virtually unlimited life make the tuning fork choppers especially suitable for dedicated applications, OEM, built into an instrument or system, and for portable systems.

Balanced operation and high „Q“ insure excellent frequency stability, low electrical drive power and low reaction forces. High flexural stiffness provicdes good resistance to shock and vibration. Tuning fork choppers are cryogenic and high temperature (200° C) capable.

The EOP-ED-Driver and the EOP-AGC-Driver are both tuning fork oscillators using the chopper as a frequency source. The AGC-Driver also provides a high amplitude stability (0.005 %) and bot sine wave and TTL reference signals.

The EOP-PLD-1C-Driver will phase lock the chopper to an external clock signal.

The EOP-PLD-2C-Driver will phase lock two choppers in a „master / slave“ chopping system.