SPECTRAL RESOLVING POWER

The resolving power of spectroscopic instruments having angular dispersion is calculated by two general methods. In one method the resolution is calculated from the angular dispersion and the diffraction, whereas in the other one it is calculated from the temporal impulse-response function of the spectroscopic instrument. It is emphasized that both methods are adequate for every spectroscopic instrument that has angular From the equality of the two formulas obtained it is demonstrated that the relation between the angular dispersion and the tilt angle of the pulse front is universal, as has recently been assumed.