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Copyright © LightForm Inc, 2017
LightForm Inc: Pioneering Analytical Hyperspectral Microscopy Since 1996
Prism Diffraction grating
Light throughput curves as a function of bandpass using a prism or a diffraction grating
Light throughput increases with increasing bandpass
As the QE of the CCD camera falls, prism bandpass increases to compensate: Net result: Higher sensitivity
CCD camera Quantum Efficiency (QE) high in the blue low in the red

PARISS®

 Hyperspectral Microscope Grating versus a Prism Comparison

Prism bandpass INCREASES with longer wavelengths
Spectral resolution: 1 - 10 nm variable 1 - 10 nm constant Wavelength range: 365 -920+ nm One octave: eg 400 - 800 nm Light throughput: >60% 365-450 nm Max of ~60% at one wavelength only >90% 450-1000 nm Above 750 nm 1-10% 2nd order pollution: None Yes: >octave 2nd order filters are required NIR efficiency: Excellent Above ~750 nm very poor to mediocre  
Grating bandpass slowly falls at longer wavelengths
LightForm_Logo
Copyright © LightForm Inc, 2017
LightForm Inc: Pioneering Analytical Hyperspectral Microscopy Since 1996
Light throughput curves as a function of bandpass using a prism or a diffraction grating
Light throughput increases with increasing bandpass
As the QE of the CCD camera falls, prism bandpass increases to compensate: Net result: Higher sensitivity
CCD camera Quantum Efficiency (QE) high in the blue low in the red
PARISS®  Hyperspectral Microscope Grating versus a Prism Comparison
Prism bandpass INCREASES with longer wavelengths
Spectral resolution:    1 - 10 nm variable 1 - 10 nm Wavelength range:    365 -920+ nm One octave: eg 400 - 800 nm Light throughput:     >60% 365-450 nm    Max of ~60% at                           >90% 450-1000 nm          one wavelength only                                               >750 nm 1-10% 2nd order pollution:   None Yes: >octave 2nd order filters are required NIR efficiency:           Excellent Above ~750 nm very poor to mediocre  
Grating bandpass slowly falls at longer wavelengths
Prism    Diffraction grating