The Exploitation Of Fible Optic Spectrometer Based On Holographic Optical Elements Used In Teaching

The spectrometer which can be used for material structure and composition analysis is known as basic equipment and actually an important part of optical instruments. Thus the way to design a low-cost and miniaturized spectrometer used in laboratory and classroom to spread the spectrometer principle and moreover lay a solid foundatioin for future professional job is of practical significance.The spectrometer performance and volume are directly affected by the corresponding optical system design which can be the core of a spectrometer. In this thesis, we discuss the optical components, working principle and characteristics of the spectrometer optical system, and propose an optical system design method-grating based on the holographic optical element. Based on the theory of holographic optics, we analyzed the Gaussian imaging properties of holographic optical elements, including the optical focal power, position of imaging, diffraction efficiency and verified that it is feasible to be a grating for the fiber spectrometer. Based on the above theory and the spectrometer working principle, we designed the optical system through the ZEMAX simulation and got the image quality evaluation and further optimization. The parameters of the grating are listed as follows:recording wavelength 575nm, the angle between the recording beams 100 degree, the focal length 40 mm, the+lth diffraction order and the aperture 10 mm; The parameters of spectrometer are as follows:the range of work wavelength 400-800nm, the volume 140* 30* 40 mm, the width of spectrum 29.1 mm. Finally, by utilizing the circuit system and the spectrometer software that have developed completely, we design the optical system and successfully collect the mercury lamp spectra. The obtained spectrum resolution is better than 8 nm and the mercury spectra results are the same as the standard ones, which means that the designed optical system is feasible.The design of this spectrometer by using the holographic element has the advantages of no ghost, little aberration, high signal-to-noise ratio, and high performance-cost ratio. Combined with the plastic shell method, it greatly reduces the production cost of the spectrometer and provides a practical and effective way to popularize the use of the spectrometer and it has a good market application prospect.