Angular aperture

About: Angular aperture is a research topic. Over the lifetime, 1771 publications have been published within this topic receiving 27257 citations.

Diffractive optical imaging lens systems

Abstract: A diffractive imaging lens, has a diffractive optical element and an aperture stop remote from the lens in the direction of the object to be imaged which corrects the lens for coma, astigmatism, and field curvature and which can be corrected for spherical aberration by using a phase corrector in the aperture of the stop. The lens provides monochromatic imaging performance superior to conventional systems, both glass lenses and holographic lenses of similar complexity. The lens system may be provided in anamorphic configuration.

Illumination system having an aspherical lens

Abstract: A lens system (10) containing an aspherical portion (18) enabling minimization of spherical aberration as well as the lens length (1). The lens system (10) includes a conical lens (12) portion providing total internal reflection of light within the lens system and an integrally attached aspherical lens portion (18). For light rays within a defined angular range of less than about ±24°, the light rays are focused on the exit aperture (for a concentrator) at a minimum lens length, l.

Swept aperture flying spot profiler

Abstract: A flying spot system uses a laser beam scanned in X and Y directions to provide surface profile information. The beam is applied to a surface under test and the time interval between the beginning of the sweep and the appearance of the beam image through an aperture is determined. This time interval is indicative of the beam angle which, through optical triangulation, is used to determine the surface height. A scan-descan arrangement and a plate with a small aperture are used to isolate a light detector from background light.

Dynamic study of a Varioptic variable focal lens

Abstract: We present real-time measurements of the wave front distortion induced by a variable focal lens. This lens, called Varioptic, is made of a transparent cell filled with twin liquids. We submit a 4.5mm in diameter lens upon a 110V voltage step inducing a optical power shift of about 25 dioptries (m -1 ) . Characteristic response time is shown to be of the order of a few 1/100s, the lens recovering its full quality after 5/100s. We present a scaling analysis of this response time versus lens size.

Optical alignment and confinement of an ellipsoidal nanorod in optical tweezers: a theoretical study.

Abstract: Within the Rayleigh approximation, we investigate the behavior of an individual ellipsoidal metal nanorod that is optically confined in three dimensions using a single focused laser beam. We focus on the description of the optical torque and optical force acting upon the nanorod placed into a linearly polarized Gaussian beam (scalar description of the electric field) or a strongly focused beam (vector field description). The study comprises the influence of the trapping laser wavelength, the angular aperture of focusing optics, the orientation of the ellipsoidal nanorod, and the aspect ratio of its principal axes. The results reveal a significantly different behavior of the nanorod if the trapping wavelength is longer or shorter than the wavelength corresponding to the longitudinal plasmon resonance mode. Published experimental observations are compared with our theoretical predictions with satisfactory results.