Question

One of the dispersive components of an optical instrument is a 0.750-meter focal length monochromator equipped with the same grating used in part (a). The grating measures 80 mm x 80 mm. Using the line/mm number calculated (a) find the first-order reciprocal linear dispersion, D-1, (in nm/mm) for this monochromator.

Answer 1

Answer:  (a) 1.11 nm/mm

Explanation:

Monochromator is a device which is used to transmits a delectable band of wavelengths of light wavelengths available at the input.

Assuming focal length monochromator  equipped with a                                    1200-groove/mm grating

The formula for the first-order reciprocal linear dispersion is

$D^{-1} = d/n*F$ where F is the focal length and n belongs to order of the first spectra.

$D^{-1} = \frac{(1/1200) mm * 10^6 (nm/mm)/}{1 * 0.75 m * (103 mm/m) } = 1.11 nm/mm$

Make sure you have used the conversion factors correctly as it will have a major impact on the calculation of the answer.