Low cost microscopy for three dimensional imaging using digital inline holographic principle

摘要

Optical microscopy is udreached a new level in terms of resolution, 3ud-udD imaging capability, flexibility of imaging different samples udwhich increase imaging complexity and the cost.. Though established labs can afford highud-udend microscopes, it remains a concern udin rural areas whereudclinics and patients cannot afford much. Semiud-udportable microscopy based on inline holographic setup is uddemonstrated where depth information as 3rd dimension can also be accessed. This setup contains only light emitting diode ud(LED), pinhole and charge coupudled device (CCD) camera. Since laser source gives rise to speckle noise and it is also cost udconstraint for developing a low cost microscopy, thus it is replaced with incoherent LED source. This setup is also known as ud‘lensless holography’ because there is udno use of lens for imaging. In conventional inline holographic setup the sample is placed udclosed to the pinhole which will restrict field of view (FOV) and diffraction signature of one particle (cell) will overlap wudith other. udTo avoid overlap of diffractioudn signatures and to increase FOV sample was placed close to CCD sensor. To test the working of udmicroscopy agarose microbeads were used. Optimization algorithm is used for reconstruction of object field from recorded udhologram.. Thus both amplitude as well auds the phase images of the microbeads is reconstructed. Instead of using microscopic udobjective to focus sample, autofocus algorithm is used to calculate the focused plane