A speckle-enhanced prism spectrometer with high dynamic range
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CitationÇetindağ, Ş. K., Toy, M. F., Ferhanoğlu, O. ve Çivitçi, F. (2018). A speckle-enhanced prism spectrometer with high dynamic range. IEEE Photonics Technology Letters, 30(24), 2139-2142. https://dx.doi.org/10.1109/LPT.2018.2879247
We present a novel spectrometer device offering a wide wavelength range and high resolution. The device builds upon a conventional prism spectrometer; however, an additional scattering medium is introduced to generate a wavelength-dependent speckle pattern on the detector array. Simultaneous use of the prism and the scattering medium allows for both improved resolution and wavelength range. The generated speckle pattern secures a significant improvement in the resolution (up to 100 folds) and dynamic range over a conventional prism spectrometer. With the proposed spectrometer, implemented using a CCD camera, we demonstrate up to 17-pm resolution at 855-nm central wavelength and 756.5-nm wavelength range revealing a dynamic range of similar to 44 500. The dynamic range could be further improved upon using a detector array having larger area and a scattering medium offering a nar-rower spectral correlation function. With further development, the proposed device could be useful in a variety of spectroscopy applications, such as deep imaging of retinal layers in optical coherence tomography.