Optical chopper CH-10

The tuning fork chopper is a FIXED FREQUENCY, electromechanically driven light chopper. 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. • One fixed frequency, between 10 Hz and 6 kHz • Aperture up to 10 mm • Small size/ lightweight • Low cost • Withstands shock and vibration • Low power drive electronics • Rugged, no wearing parts • High reliability, long life • High frequency stability (to 0.005%) • High amplitude stability (<0.01%) • Vacuum operation (to 10-10 Torr) 1 • High/low temperature operation (Cryogenic temperatures to 200 C) 1 • Jitter free operation • No radiated electromagnetic interference (EMI) • Reference signal available • Metal vanes are standard, mirrors, prisms or lenses optional 1 • Single vane for alternate beam chopper 1 Chopping frequency ranges from 10 Hz to 6 KHz, apertures up to 15mm are practical in the lower frequencies (under 100 Hz), 0.5mm at 3 KHz and 0.2mm at 6 KHz. If the beam size is limiting 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. 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.