Quantitative phase micro-imaging method based on annular programmable LED lighting

Abstract

The invention discloses an efficient quantitative phase micro-imaging method based on annular programmable LED lighting. The method comprises the following steps that: system optical transfer function derivation under a partial coherent lighting imaging system is performed; phase transfer function derivation under weak object approximation is performed under inclination axis symmetric coherent point light source lighting; extension from an optical axis symmetric coherent point light source to a discrete annular point light source is performed, and incoherent superposition of the system transfer function under the condition of optical axis symmetry is performed; original image acquisition is performed; and quantitative phase deconvolution reconstruction is performed. The system phase transfer function of the inclination axis symmetric point light source under the condition of partial coherent lighting is derived and popularized and applied to the optical transfer function of the discrete annular point light source; and the annular lighting aperture is enabled to be flexible and adjustable by the programmable control mode of the LED array so as to be suitable for the microscope objective of different numerical aperture and enhance the compatibility and flexibility of the system.

Description

technical field [0001] The invention belongs to optical microscopic measurement and imaging technology, in particular to a high-efficiency quantitative phase microscopic imaging method based on annular programmable LED illumination. Background technique [0002] Phase recovery is an important technology in optical measurement and imaging, and plays an important role in both biomedical and industrial inspection. The most classic quantitative phase measurement method is interferometry (Cuche E, Bevilacqua F, Depeursinge C. Digital holography for quantitative phase-contrast imaging[J]. Opticsletters, 1999, 24(5): 291-293.) The beam produces two beams of light. The object light passes through the sample and then interferes with the reference light, resulting in interference fringes. The phase delay of the object can be obtained through the demodulation algorithm. However, the interferometry method has particularly obvious disadvantages: (1) interferometry generally requires a h...

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Problems solved by technology

However, the interferometry method has obvious disadvantages: (1) interferometry generally requires a highly coherent light source (such as a laser), which requires a more complex interferometric device; (2) the introduction of an additional reference optical path leads to requirements for the measurement environment (3) Speckle coherent noise introduced by highly coherent light sources limits the spatial resolution and measurement accuracy of the imaging system

Here there is the selection of imaging resolution and image measurable contrast. The contrast of the image is the strongest under the condition of coherent illumination, but the imaging resolution at this time is only determined by the numerical aperture of the objective lens.

When the coherence coefficient σ=1, the imaging resolution can be extended to twice the numerical aperture resolution of the objective lens, but the contrast of the image information is too weak for the camera to collect useful signals

Although partially coherent illumination has been introduced into quantitative phase imaging based on the light intensity transport equation (Gureyev TE, Roberts A, Nugent K A. Partially coherent fields, the transport-of-intensity equation, and phase uniqueness [J]. JOSA A, 1995, 12(9):1942-1946.[2]Paganin D,Nugent K A.Noninterferometric phase imaging with partially coherent light[J].Physical review letters,1998,80(12):2586.), but can not avoid imaging The trade-off between resolution and image detectable contrast

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