Design of concave holographic grating monochromator

An application of monochromator in fiber optic sensing system is proposed. By analyzing the function of optical path, the principle of aberration correction and its correction effect for the type IV concave holographic grating, a small-size monochromator is designed based on the grating. In the monochromator, a self-focusing lens is used as the entrance slit and the collimating component while a PIN photoelectric diode is acted as the receiving component. A step motor drives the grating to rotate which in turn scans the optical spectrum. A program based on LabVIEW controls a data acquisition card to output digital signals, and to display the acquired spectrum. The detection of light with a single wavelength is realized with the simple and low-cost monochromator.