An echellette grating that contains 1450 blazes/ mm was irradiated with a polychromatic beam at an incident angle 48 to the grating normal. Calculate the wavelengths of radiation that would appear at an angle of reflection of 20D+10, and 0 (angle r, Figure 721 ). (a) What is the width of grove per blaze (in nm )? (b) Calculate the wavelength of radiation for the first order of reflection. (c) What is the wavelength of radiation for the 2nd order of reflection? A grating monochromator with a reciprocal linear dispersion of 1.2nm/mm is to be used to separate the sodium lines at 588.9950nm and 589.5924nm. In theory, what slit width would be required