Model 272 High Throughput f/2 Monochromator Aberration Corrected Grating Design Fast f/2 Optical System Wavelength Range from 185-nm to NIR Aberration Corrected Grating Use for Scanning or Array Detection Many Optional Fiber Accessories Compact, Lightweight Construction Operates in any attitude

The Model 272 monochromator contains a large, 100-mm diameter diffraction grating. This guarantees a large solid angle of light collection. The gratings corrected design reduces optical aberrations. This improves the spectral resolution of this high throughput optical system. The Model 272 is a versatile research grade monochromator. It delivers high throughput and moderate spectral resolution. Usable in any attitude, standard features of much larger McPherson monochromators have found home in this high efficiency f/2 monochromator.

The Model 272 opto- mechanical system is ruggedly constructed for use in any environment. The lapped wavelength drive screw will provide years of accurate wavelength positioning. The grating scans are controlled by the optional Model 789A-3 digital scan drive system. McPherson signal recovery and control software can be used. Most McPherson accessories work with this instrument. It is best to inquire to make sure the f/2 beams work at full capacity.

Specifications

McPherson Model 272, 200-mm focal length f/2 High Throughput Monochromator

Focal Length	200-mm
Angle between Entrance and Exit Beams	38-degrees
f / No.	2
Grating Size	104-mm diameter
Wavelength Accuracy	2-nm (on mechanical counter with 1200 G/mm grating)
Wavelength Reproducibility	0.1-nm (with 1200 G/mm grating)
Focal Plane	25-mm, multiply dispersion by the width of your detector for range
Wavelength Range	refer to grating of interest for range

Performance of the Model 272 with various gratings:

Grating (G/mm) (others available)	2280	1710	1140	570
Wavelength Range from about 185-nm to	650 nm	950 nm	1250 nm	2500 nm
Grating peak response at	450 nm	550 nm	650 nm	1200 nm
Resolution (nm) at 313.1-nm	0.7	0.9	1.6	3.7
Dispersion (nm/mm)	2	3	4	8

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Focal Plane Arrays The Model 272 uses a concave grating that focuses and disperses light. The grating has aberration correction built to minimize spherical aberration and astigmatism. When used with a focal plane array the detector must be brought to the instrument focal plane that forms along a modified Rowland circle. Most detectors do not fit into the limited available space. There may be mechanical, width and mounting restrictions so please contact us to discuss the options. Please inquire if you are planning to mount an array detector to your model 272.

Model 272 Light Canon The Model 272 is available with fitted light sources, fiber optic accessories or post-monochromator optics for imaging the exit slit to a sample plane. The Model 272 shown here is equipped with an f/2 matched light source (Model 618, 100-W tungsten halogen) and an output lens assembly for projecting light to samples.

CL Application The images at left show a thin slice of rock (biotite-hornblende). The photo (far left) was taken in transmission mode, typical in conventional microscopy. The photo (near left) was excited by cathode luminescence (CL). The samples on the microscope stage are excited by cathode luminescence (a 20 keV electron beam) until they emit light, which subsequently is analyzed spectrally with the McPherson Model 272. The same sample is shown in both photos. The CL excitation and spectral analysis reveals details like never before! The Model 272 simplifies spectral identification of the elements involved. Learn a little more about this application by following the link to our systems page.htm