fluorescence spectrum
Microscopic defects film thickness
Solar Cell IV
Semiconductor Material Testing
Andor Spectrometer
fiber optic spectrometer
Laser spectral analysis
single-point detector
imaging camera
Electrical Test Instruments
EDMUND Optics
Newport Products
Crystal Optical Products
SR540 Optical Chopper
Single Beam Experiment |
The SR540 chopper meets all your optical chopping requirements, from simple measurements to dual beam and intermodulation experiments.The SR540 features a 4-digit frequency display, front panel frequency control, analog voltage frequency control, and two reference outputs with selectable operating modes. Two anodized aluminum blades are available: a 5/6 slot blade for frequencies up to 400 Hz and a 25/30 slot blade for frequencies up to 3.7 kHz. reference outputs are provided for the frequency corresponding to each time slot row, as well as sum and difference frequencies.
Optical Chopper Applications
Single Beam Experiment
In this application, a single beam is chopped by the outer row of slots and the reference output of the right BNC is used to lock the lock-in amplifier to the chopping frequency. It is also possible to use the inner row of slots, in which case the left BNC will be the reference output. In either case, the REFERENCE MODE switch is in the UP position.
Dual Beam Experiment
Dual Beam Experiment |
In this arrangement, the output from a single source is separated and chopped at two different frequencies by two rows of chopper slots. One beam passes through the experiment and the other is used as a reference beam. The beams are recombined and sent to the same detector. Two phase locks were used to detect ƒ inside, corresponding to the experimental signal, and ƒ outside, corresponding to the reference beam. If the signal detected in the experimental arm is proportional to the signal detected in the control arm, effects due to variations in source intensity and detector efficiency are eliminated.
English