Disclosed is a coherence-adjustable digital holography system. More particularly, the coherence-adjustable digital holography system includes a light source part for generating low-interference light; a dispersion part for dispersing the generated light, an adjustment part for adjusting coherence by adjusting a spectrum bandwidth of the light which has passed through the dispersion part; and a detection part for detecting a holographic image of a subject from the adjusted light. In accordance with such a configuration, an interference fringe may be easily obtained through coherence adjustment, whereby the accuracy of a detected holographic image may be improved.

Disclosed are a holographic writing method and apparatus capable of re-writing (updating) holographic information and quickly writing the holographic information with high efficiency. In an embodiment, a holographic writing method for writing holographic information by emitting a beam at a holographic recording medium containing a photo-responsable polymer material having photoisomerization characteristics that change a molecular structure thereof by absorbing light energy, writes the holographic information by using a writing wavelength different from a maximum absorption wavelength in a light absorption spectrum of photoisomer molecule structures of the holographic recording medium. The maximum absorption wavelength is a wavelength at which light absorption rate is maximum in the light absorption spectrum. A difference between the light absorption rates of the photoisomer molecule structures at the writing wavelength is less than a difference between the light absorption rates of the photoisomer molecule structures at the maximum absorption wavelength.

The present disclosure discloses a method and apparatus for preparing a femtosecond optical filament interference direct writing volume grating/chirped volume grating. The method is characterized in that optical filaments are formed in glass by using femtosecond pulse laser, and plasma is controlled to quickly scan in the glass and etch a volume grating or chirped volume grating structure by adjusting the focal length of convex lens, laser energy and movement of motor machine. The apparatus includes a femtosecond pulse laser module, a pulse chirp management module, a pulse time domain shaping module, a laser separation and interference module, a glass volume grating processing platform module and a camera online imaging module.

Systems and methods for sub-aperture correlation based wavefront measurement in a thick sample and correction as a post processing technique for interferometric imaging to achieve near diffraction limited resolution are described. Theory, simulation and experimental results are presented for the case of full field interference microscopy. The inventive technique can be applied to any coherent interferometric imaging technique and does not require knowledge of any system parameters. In one embodiment of the present application, a fast and simple way to correct for defocus aberration is described. A variety of applications for the method are presented.

The present invention generally extends to methods, systems, and devices that advantageously employ holograms to store and retrieve information about objects, and to compare objects. Methods include generating first and second holograms of image spectral cross sections comparing the holograms and using a photometer to analyze the comparison result. Computer program products are described for use in differentiating spectral components of spatial cross sections of image pixels.

A system for generating a lithographic image contains a a light source that emits a diverging light beam and a reflective concave curvilinear surface onto which the diverging light beam falls and which reflects the diverging beam in the form of a converging beam. A digital hologram, which is placed into a diverging beam between the light source and the reflective surface, is coded in accordance with the lithographic image either preliminarily or dynamically, with the use of a spatial light modulator. From the curvilinear surface the spatially modulated beam is reflected in the form of a converging beam which falls onto an image-receiving substrate that is located in the image restoration plane and on which the lithographic image is generated.

Systems and methods for sub-aperture correlation based wavefront measurement in a thick sample and correction as a post processing technique for interferometric imaging to achieve near diffraction limited resolution are described. Theory, simulation and experimental results are presented for the case of full field interference microscopy. The inventive technique can be applied to any coherent interferometric imaging technique and does not require knowledge of any system parameters. In one embodiment of the present application, a fast and simple way to correct for defocus aberration is described. A variety of applications for the method are presented.

Disclosed is a coherence-adjustable digital holography system. More particularly, the coherence-adjustable digital holography system includes a light source part for generating low-interference light; a dispersion part for dispersing the generated light, an adjustment part for adjusting coherence by adjusting a spectrum bandwidth of the light which has passed through the dispersion part; and a detection part for detecting a holographic image of a subject from the adjusted light. In accordance with such a configuration, an interference fringe may be easily obtained through coherence adjustment, whereby the accuracy of a detected holographic image may be improved.

Computer-generated holographic display systems are described with improved image quality when used with illumination sources other than single mode lasers, such as broader emission light sources including LEDs and multi-mode lasers.

Provided is a high-resolution reflection tomographic imaging system and method. The high-resolution reflection tomographic imaging system of the present disclosure may include an objective lens, a tube lens, a camera, an illumination element configured to introduce temporally coherent and spatially incoherent light, and a semi-reflective surface element configured to split the light into a sample and a reference beam between the tube lens and the camera, such that a sample beam from the sample and the reference beam cause interference for tomographic imaging.