3.2
SM302 Spectrograph Optical Layout
Figure 3
SM302 Optical Path
3.3
SM302 Spectrometer Wavelength Ranges.
The grating angle is restricted to angles between 0 to 70 degrees. The upper restriction is imposed because
the grating is almost edge-on to the incident beam beyond this angle. From these restrictions, one may use the grating
equations to calculate the valid ranges and step sizes for any particular grating. The table below lists the maximum
wavelength for each grating set in the Spectrograph’s software.
UPPER WAVELENGTH SCAN LIMIT AND MAXIMUM WAVELENGTH INCREMENTS PER
ANGULAR STEP FOR DIFFERENT GRATINGS
(Lower wavelength scan limit is zero)
Grating Upper Limit
Grv/mm nm
1200 1500
600 3000
300 6000
150 12000
75 24000
50 36000
45 40000
3.4
Using the LPF 1300 Filter
On
the
SM302
Extended
models it might be necessary to use the LPF 1300 filter. Mounted on the side of the
unit is a black knob with an In and Out position. The LPF 1300 will filter out any first or second orders below 1300nm
(
IN
position). With the LPF 1300 filter in the
OUT
position the LPF 900 filter will filter any first or second orders
below 900nm.
Spectral Products
2659-A Pan American Frwy., NE Albuquerque, NM 87107 Tel (505) 343-9700 Fax (505) 343-9705
www.spectralproducts.com
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Focusing Mirror
Collimating Mirror
SMA Slit Flange
CCD Array
Folding Mirror
Grating