Raman Spectroscopy Using a Spatial Heterodyne Spectrometer

The SHS Raman spectrometer has many unique advantages over all previously reported Raman spectrometers. Typical examples include:

[A] Advantages over Monochromator (MC) for Raman

1. Much higher etendue or throughput

2. Wide-area collection capability

3. Much higher resolving power in a much smaller and lighter package

4. Much larger input aperture compared to MC slit

[B] Advantages over Michelson Interferometer (MI)

1. No moving parts in SHS allows using a pulsed laser and gated detector so it can be used in ambient light conditions, and so an entire Raman spectrum can be acquired with each laser pulse. This allows a pulse around the laser wavelength to increase the resolution in the deep UV.

2. SHS gives higher resolving power in the deep UV using much lower tolerance optics.

3. SHS allows the use of simple wedge prisms to further increase the acceptance angle, not possible or easy in a moving mirror resign like the MI

The Spatial Heterodyne Spectrometer (SHS) is used to measure wide area diffuse stellar emission. It is also used for absorption measurements.

It has unique characteristics which include high optical throughput (e.g., large etendue), wide acceptance angle which gives the ability to measure wide-area, extended sources of light, very high resolving power, large entrance aperture [as opposed to the to a monochromator slit], small size in proportion to the resolving power, and no moving parts. It is implemented differently than all prior applications of the SHS spectrometer.