Lightpipes are essential to automotive interior illumination systems. These light distribution systems are constrained by geometrical complexity, which makes both analysis and fabrication difficult. Their development depends on empirical procedures that are often inefficient and time-consuming. We review the successful modeling procedure of one complete automotive illumination light-pipe system, which includes a light source and a light pipe. The success of modeling is verified by comparing results to experimental measurement. A simple method of light-pipe evaluation based on nonsequential ray trace optical modeling for the automotive illumination industry is demonstrated. Extensive modeling of the light sources for these systems is also included.
Recently the lens fabrication technique is developed so fast that an aspherical surface is often used to achieve better imaging performance or reduce number of elements. Especially the popularity of micro-optics and miniature imaging system makes the use of aspherical optics very common. However the metrology of aspherical micro-optics has been disregarded and outpaced by the fabrication technique. It results in the lack of ignorance of metrology for aspherical micro-optics. This paper suggests the simple and cost-effective methodology for aspherical micro-optics by using computer generated hologram (CGH). Although the CGH technique is well-known and well-established technique for relatively larger aspherical optics, it is seldom used for micro-optics testing where there is higher demand of aspherical optics testing. By reporting the success of aspherical micro-optics testing in this paper, we confirm that CGH technique will play an important role to answer new demand of metrology.
We are developing a multi-modal miniature microscope (4M device) for imaging morphology and cytochemistry in vivo and providing better delineation of tumors. The 4M device is designed to be a complete microscope on a chip, including optical, micro-mechanical, and electronic components. It has advantages such as compact size and capability for microscopic-scale imaging. This paper presents the recent imaging experiment of 4M device including trans-illumination imaging, TIR illumination imaging and fluorescent imsging. We built a multi-modal imaging test-bed to demonstrate multi-modality of 4M device. In this paper, we present imaging experiment results by implementing various imaging modality with cervical cancer cells. In order to enhance image contrast, some imaging modality uses cells attached with contrast agency such as silver nano-particles. Imaging results indicate that the 4M prototype can resolve cellular detail necessary for detection of precancer.
Most conventional imaging systems suffer from unwanted and unexpected stray light that is often caused by reflections and scattering from optics and opto-mechanical features. This problem is easily missed during a design procedure that concentrates on improvement of imaging performance. The problem becomes apparent at the final step of production in most cases. If an imaging system consists of micro-optics, a stray light problem may become more difficult to solve due to the system's micro-scale size.
The purpose of this stray light analysis is to improve imaging performance of the multi-modal miniature microscope (4M). The 4M device is a complete microscope on a chip, including optical, micro-mechanical, and electronic components. The 4M device is potentially a useful tool for early detection of pre-cancer due to its very compact size and capability for microscopic-scale imaging. Before actual fabrication of this device, however, we built the same geometry as the real 4M device in a commercial non-sequential ray tracing code and implemented stray light analysis of 4M device.
Our findings indicate that most of the stray light in a 4M device is created by reflection from optics that are nominally supposed to be transparent. Due to a low signal level associated with the object, it is required to add high quality anti-reflection coatings on optics to achieve reasonable SNR.
Recently new technologies for detecting biomolecules have been developed and are opening a new era of medical imaging. Chemiluminescence and fluorescence are emerging as promising tools for these tasks. These molecules emit optical photons that can be observed outside the body. Unfortunately, they are heavily scattered and absorbed in biological tissue. This is an obstacle for determining a way of mapping an original source distribution. In order to overcome this obstacle, we suggest a new concept, Optical Emission Computed Tomography and test its feasibility with computer simulation.