Three-wavelength carrier-frequency multiplexing common-channel digital holographic detection device and method

Abstract

The invention provides a three-wavelength carrier frequency reuse common-path digital holographic detection device and method. A first color-combining prism is utilized to merge three-wavelength incident laser into one beam, after the one beam sequentially flows through a collimation beam expanding system, a to-be-detected object, a first lens and a non-polarization splitting prism, focusing reference light and object light are formed; the reference light irradiates on a small hole reflector and is reflected; the object light flows through a second color-combining prism and then is divided into three-wavelength object light which respectively irradiates on a triangular reflector and is reflected, the reflected light further flows through the second color-combining prism and is combined into one object light beam; the reflected reference light and the reflected object light are merged through the second color-combining prism into one beam and then flows through a second lens, interference is generated on a light reception surface of an image sensor to form a three carrier frequency reuse hologram, the image sensor is utilized to acquire the hologram which is uploaded to a computer, and a to-be-detected phase is calculated. The method is advantaged in the three light beam common-path structure is employed, the structure is simple, and good stability is realized; only the black white image sensor is needed to record the hologram, and three-wavelength hologram separation is accomplished through the simple algorithm.

Description

technical field [0001] The invention belongs to the field of digital holographic detection, and in particular relates to a three-wavelength carrier-frequency multiplexed common-channel digital holographic detection device and method. Background technique [0002] Due to its unique advantages such as non-contact, full-field quantification, and three-dimensional imaging, digital holographic detection technology has been widely used in the measurement fields of biomedicine, micro-nano devices, and optical micro-machining as an extremely important test and analysis method. However, due to the distribution of sine and cosine functions of hologram fringes, the phases obtained by traditional single-wavelength digital holography are mostly wrapped phases, which require complex and time-consuming algorithms to realize phase unwrapping. Three-wavelength digital holography uses three beams of illumination light to synthesize an equivalent wavelength larger than the thickness of the sam...

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Problems solved by technology

[0003] Patent CN106569402A "A Color Separation and Digital Processing Method for Multi-Wavelength Digital Holograms" first uses a Bayer-type color camera to separately collect single-wavelength digital holograms of objects under three-color laser irradiation, and obtains the crosstalk coefficient between the three colors through numerical processing Matrix; then collect multi-wavelength digital holograms irradiated by three-color lasers at the same time, and use the crosstalk coefficient matrix to eliminate the crosstalk between the three channels caused by the incomplete selectivity of Bayer color filters to different wavelengths of light, realizing a single digital hologram holographic Figure 1 Record information of multiple wavelengths at one time, but this method not only has high cost, low resolution, but also complicated operation, which cannot realize online real-time detection

[0004] Patent CN101452253B "A Method for Acquiring Color Digital Holograms" utilizes black-and-white area array CCD and multi-recording wavelength lensless Fourier transform hologram recording optical path to realize three-wavelength digital holographic imaging, but this method still needs to record each wavelength separately Hologram, and requires complex algorithms to reproduce imaging, poor real-time performance, and because of the use of separate optical paths, poor anti-interference ability

[0005] Patent CN105717774A "A device and method for real-time recording of color digital holograms" under the condition that the illumination angles of the object beams are consistent, the irradiation angles of the reference beams are adjusted respectively, and holograms containing different carrier frequencies of each wavelength are obtained through one exposure to realize dynamic Real-time holographic recording of colored objects, but the light beams of each wavelength of the device pass through different positions in space, which not only results in a large and complex structure, difficult adjustment, but also poor anti-interference ability

[0006] French SONG Qinghe et al. (Song Q, Wu Y, Tankam P, et al.Research on therecording hologram with Foveon in digital color holography[C],PhotonicsAsia.International Society for Optics and Photonics,2010) use color camera to record hologram, can Making each wavelength beam share one optical path greatly simplifies the system structure and reduces the complexity of system operation. However, because of the use of color cameras, not only the cost is high, but also complex algorithms are required to suppress the crosstalk between each wavelength; at the same time, because the color camera is used Separate optical path, poor anti-interference ability

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