We present a compound adaptive objective lens in which a water-filled membrane lens is inserted into a front group (one lens) and a back group (two lenses). This adaptive objective lens works in the ultrabroad near infrared waveband (760nm ~ 920nm) with the volume scan of > 1mm3 and the resolution of 2.8 μm (calculated at the wavelength of 840 nm). The focal range is 19.5mm ~ 20.5mm and the numerical number is 0.196. The size of the adaptive lens is 10mm (diameter) × 17mm (length). This kind of lens can be widely used in three-dimensional (3D) volume biomedical imaging instruments, such as confocal microscope, optical coherence tomography (OCT), two photon microscope, etc.
We demonstrate a 1050-nm spectral domain optical coherence tomography (OCT) system with a 12 mm imaging depth in air, a 120 kHz A-scan rate and a 10 μm axial resolution for anterior-segment imaging of human eye, in which a new prototype InGaAs linescan camera with 2048 active-pixel photodiodes is employed to record OCT spectral interferograms in parallel. Combined with the full-range complex technique, we show that the system delivers comparable imaging performance to that of a swept-source OCT with similar system specifications.
Before the aerial photographic task, the cameras focusing work should be performed at first to compensate the defocus caused by the changes of the temperature, pressure etc. A new method of aerial camera auto focusing is proposed through traditional photoelectric self-collimation combined with image processing method. Firstly, the basic principles of optical self-collimation and image processing are introduced. Secondly, the limitations of the two are illustrated and the benefits of the new method are detailed. Then the basic principle, the system composition and the implementation of this new method are presented. Finally, the data collection platform is set up reasonably and the focus evaluation function curve is draw. The results showed that: the method can be used in the Aerial camera focusing field, adapt to the aviation equipment trends of miniaturization and lightweight .This paper is helpful to the further work of accurate and automatic focusing.
The Reflective Four-Sided Pyramid can be used to divide one light beam into four beams in image space and to achieve the joint purpose of the four CCDs. It also causes the vignetting effect in the joint areas of the image. The calculation of the vignetting distribution caused by the Reflective Four-Sided Pyramid can give us the theoretical basis to guide the further work of image stitching and image luminance processing.
Proc. SPIE. 7658, 5th International Symposium on Advanced Optical Manufacturing and Testing Technologies: Optoelectronic Materials and Devices for Detector, Imager, Display, and Energy Conversion Technology
KEYWORDS: Signal to noise ratio, Linear polarizers, Optical filters, Optical design, Sun, Stars, Polarization, Imaging systems, Polarizers, CCD cameras
How to see the stars in daytime? A new idea is described here in this paper which uses a combination of two methods:
one is traditional spectral filtering method and the other is a new attempt on daytime star detection--polarization method.
Each of these two method's principle of work, scope of application and limitation on daytime star detection are
introduced in detail; and the advantage of the combination is discussed accordingly. Based on the demand of the daytime
star detection, a device is designed and its optical system and mechanical structure are also analyzed in this paper. At last,
a further discussion of the existing problems and the possible improvements of the current device are presented.