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Microinjection molding is an effective mass production technology to replicate microcomponents. However, compared with conventional injection molding, microinjection molding requires an adapted processing due to larger surface-area-to-volume ratios, as well as higher shear and cooling rates. Since the functionality of the final parts depends on their defect-free fabrication, a fast, robust, and reliable...
In this paper we present a new approach for the measurement of multiple digital holograms at different positions in space that can be combined to one high resolution hologram. The reconstruction is based on a phase shifting approach, where the CCD sensor and the reference wave are moved simultaneously along different positions in x and y. An inclination of the reference wave induces a phase shift...
We present a method that significantly reduces the speckle effect in holographic projection. It is based on zero-padding the predefined projected intensity and calculating an extended phase distribution using an optimized iterative approach based on the generalized projection method. The extended phase distribution is divided into several finite ones with the size of the spatial light modulator (SLM)...
In this paper, we present a new method for the design of diamond turned holograms (DTHs) for image formation with multiple wavelenghts. The approach allows the design of DTHs that reconstruct different independent intensity distributions in the far field when illuminated with different wavelengths. It is based on a new approach that allows the utilization of the nonlinear conjugate gradient (NCG)...
We present a novel design of an angular multiplexed system that facilitates dynamic synthesis of predefined wave fields using a 3D diffractive optical element. In this system several angular projections of given far-field intensities are encoded in a single computer generated volume hologram (CGVH). A spatial light modulator (SLM) is used to modulate an impinging plane reference wave thus allowing...
We present a novel optofluidic multiplexing and switching device in which light switching between different fibers via movable droplets in a liquid core waveguide is realized. The Poly-(dimethylsiloxane) (PDMS)-based device uses aqueous droplets in high index oil to create a movable interruption in the waveguide. Light is thus coupled out at the position of said droplet and then back into adjacent...
We present an optoelectronic approach to enhancing the resolution of digital holograms. By combining interference patterns of differently shifted wave fields a high resolution measurement of the object waves complex amplitude is obtained. A spatial light modulator is used to generate the phase only transfer functions of wave field shifts.
We present a method for the design of diamond turned holograms for the reconstruction of arbitrary intensity distributions in a Fresnel domain. Existing methods are limited to the reconstruction of intensities in the far field, which imposes limitations to the optical setup. Theory and experimental verification of the new approach are presented.
We present an opto-electronic sub-pixel shifting method for resolution enhancement in monochromatic imaging. It is based on a Spatial Light Modulator (SLM) in the Fourier domain of a 4f-configuration. The SLM is used to modulate the incident light with the transfer function of a lateral subpixel shift. Therefore, a set of laterally shifted representations of the wave field incident on the 4f-setup...
We show that phase retrieval from a set of intensity measurements can be used to determine the thermally induced deformation of a diffusely reflecting surface. The presented approach is based on an experimental setup with a spatial light modulator (SLM) located in the Fourier domain of a 4f-configuration. The SLM is used to modulate the incident light with the transfer function of propagation. Since...
We provide an overview over recent applications of electronically addressed liquid crystal spatial light modulators (SLM) in the field of optical metrology. Three particular examples are considered: A shear interferometer, a setup for phase retrieval from a set of intensity measurements and a digital holographic sensor which allows for the electronic adaption of the reference wave.
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