How Does the DeSa Monochromator - the Optical Bench of an Olis RSM 1000 - Work?

At the heart of the RSM is the DeSa monochromator, a patented 0.25-meter subtractive double-grating monochromator capable of 1,000 wavelength scans/second. In the middle plane of the DeSa monochromator, instead of the stationary central slit found in other monochromators, there is a moving slit or slits. This invention replaces a fixed slit that we call a "ScanDisk Module" in the middle plane. This ScanDisk houses a spinning disk containing, typically, 16 slits (shown here). A synchronous motor (the only 'mechanical' component of the RSM) spins the disk at a speed of 62.5 Hz, which enables the RSM to collect an incredible 1,000 scans per second (16 slits revolving at 62.5 times per second = 1,000 scan scans/second).

The RSM maximizes data collection by gathering millisecond "snap-shots" (spectral scans) of a rapid reaction. This unprecedented scanning rate is achieved with high light throughput (F/4.5), negligible stray light (10^-3and less), milliabsorbance (and less noise, and nanometer resolution (0.1-20 nm, user selectable).

The more common additive double monochromator yield a spectrally dispersed output beam. Because the DeSa monochromator is "subtractive", the entire output beam is spectrally homogeneous, regardless of the resolution you choose.

Photometric accuracy is better than competing technologies, e.g. CCD diode array, since the RSM utilizes a double monochromator, the optical system is dual-beam (sample and reference channels), and photomultiplier tubes (rather than less sensitive choices) are used as the detectors.

Data are collected by twin channel 14 bit 2 MHz A/D cards and all data processing is supported by sophisticated data analysis software.

SEE ALSO: What does 1,000 scans/second look like?
View a dynamic simulation of 1,000 scans/second!