Plano-convex Cylindrical Lens Research Articles

Simulation of plano-convex cylindrical lens effects on photovoltaic solar cells efficiency

A method for control and modification of solar cell efficiency using a plano-convex cylindrical lens is proposed. Optical effects of a plano-convex cylindrical lens placed on a solar cell are detailed theoretically and numerical simulations are used to modify the efficiency of the cell. It was found that the lens could reduce the incident angle of the beam and enhance the solar cell voltage. The output power from the solar cell could be controlled using this lens during the day and a modification method is proposed in order to gain more output power from a solar cell. This method is a low cost and green method to gain controllable output voltage from the photovoltaic solar cells. Experiments confirm the effectiveness of this method.

Large astigmatic laser cavity modes and astigmatic compensation

In this paper, it was experimentally verified that anisotropic (astigmatic) Hermite–Gaussian modes can be generated from a hemi-cylindrical cavity and can be transformed into Laguerre–Gaussian modes by using an extra-cavity plano-convex cylindrical lens which can modify different beam divergence angle in the x–z and y–z planes. By controlling the off-axis pumping and the angle of the extra-cavity cylindrical lens, a variation in laser patterns was observed. Moreover, several additional relationships under different conditions have been analyzed. All experimental results corresponding to the theoretical analysis, and the role of the hemi-cylindrical cavity can be completely understood by comparing the theoretical and experimental results.

A compact and high-power silicon-wafer solar strip-cells-array module integrated with an array concentrator**Project supported by the National Natural Science Foundation of China (Grant Nos. 61377021 and 61671329).

A compact, low-cost and high-output-power silicon-wafer solar strip-cells-array module (SCAM) was experimentally demonstrated. The proposed SCAM consisted mainly of a silicon-wafer strip-cell sparse array and low-concentration-ratio array concentrator based on an epoxy resin polymer (ERP) cylindrical plano-convex lens. A polymer replication process based on a polydimethylsiloxane mold was used to fabricate the ERP lens array concentrator. The results show that 46.94% of the silicon-wafer cell was saved in the designed SCAM. Moreover, the output power of the SCAM with a low concentration ratio of 8 suns was improved by 8.6%, compared with a whole piece of a conventional silicon-wafer solar cell with the same area as the module. The proposed method encapsulating solar cells provides a means to reduce the usage of silicon cells in modules as well as improving the output power of modules.

Calibration for the sensitivity of multi-beam angle sensor using cylindrical plano-convex lens

A highly sensitive and compact multi-beam angle sensor (MBAS), which utilizes the principle of operation of an autocollimator, was developed to detect the differential of the local slope components (angle difference) of a point on the mirror surface and using Fourier series, we can obtain the profile data from the angle difference. In order to investigate the application of the MBAS for high precision aspheric surface measurements, two types of calibration methods using plane mirror and cylindrical plano-convex lens has been proposed to measure the sensitivity of the MBAS. The calibration data analysis results using plane mirror agree well with the measurement results of the cylindrical plano-convex lens data. Comparison of the two methods confirms that the second method (using cylindrical plano-convex lens) is more adapted for measurement with ultra high level of uncertainty. Further, the second method is simple, corresponding to a direct calculate in the sensitive parameters aiming to minimize the cost.

Simple method for measuring the cleave angle of optical fiber facets by using the nodal points of a cylindrical lens

A simple experimental setup for measuring the cleave angle of optical fiber facets by using a plano-convex cylindrical lens is presented. In this method, a laser beam is coupled to the perpendicularly cleaved input fiber facet and propagates up to the output end, where the fiber facet is cleaved at a certain angle. The divergent beam emerges from the output end fiber at an angle determined by the cleave angle and impinges at the cylindrical lens through a very narrow slit. The slit is placed in contact with the vertex of the convex side of the cylindrical lens and parallel to its axis. The slit-lens assembly is moved perpendicular to the optical axis of the lens so that the marginal rays of the incident beam pass through the slit. Using the output angles from marginal rays of the refracted beam by the cylindrical lens, it is possible to calculate the output angle of the principal ray and, by measuring this angle, the cleave angle can be estimated.

Focusing by a Cylindrical Plano Convex Lens of Chiral Medium

In this paper, the focussing of electromagnetic fields from a cylindrical plano convex lens composed of chiral media is analyzed using Maslov's method. The chiral medium is described electromagnetically by the constitutive relations D = ε E + jγ B and H = jγ E + 1/μ B. In this study, the propagation of electromagnetic waves through a cylindrical plano convex lens of chiral medium is formulated for normal incidence. The effects of the chirality on the polarization and the intensity of the refracted field from a chiral cylindrical plano convex lens around the caustic region are discussed. Numerical computations are made using Maslov's method to illustrate the effects of the chirality on the intensity of the refracted field from the chiral lens. The results are also compared using Kirchhoff's approximation which are in good agreement.

Optical design of a line-focused forward-viewing scanner for optical coherence tomography

We report an optical design of a line-focused forward-viewing optical coherence tomography (OCT) scanner for high-speed endoscopic imaging. To avoid a complex lens system, an off-axis cylindrical mirror is used for focusing the line illumination onto the sample surface. Because of its insensitivity to the broadband spectrum, the mirror-focused scanner improves the image quality compared to a lens-focused scanner. In this work, a feasibility study is carried out on the use of a reflective-optics-focused line scanner in OCT imaging, instead of the traditional refractive optics scanner. The Strehl ratio, chromatic focal shift, and field analysis were carried out for a plano-convex cylindrical lens, an achromatic cylindrical lens, and a cylindrical-mirror-focused scanner. ZEMAX optical modeling analysis showed that mirror-focused scanning provides better Strehl ratio in comparison to plano-convex cylindrical-lens-focused scanning, and that the Strehl ratio is comparable to achromatic cylindrical-lens-focused scanning. However, field analysis on the edges of the scanning elements within the scan range shows that mirror-focused scanning is more robust when compared to a cylindrical achromatic lens. Overall, a mirror-focused scanner shows better performance compared to lenses.

Study of Focusing of Field Refracted by a Cylindrical Plano-Convex Lens Into a Uniaxial Crystal by Using Maslov's Method

High frequency fields refracted by a geometry, which contains a plano-convex lens placed at a certain distance from a plane uniaxial interface, are derived by using Maslov's method. Maslov's method predicts the field in the caustic region by combining the simplicity of ray and generality of the transform method. Numerical computations are made for the field pattern around the caustic. The results are found in good agreement with results obtained using Kirchhoff's approximation.

White-light supercontinuum interference of self-focused filaments in water

The generation of a horizontal array of stable white-light continuum (WLC) filaments in water is observed using a cylindrical planoconvex lens. The widths of these filaments are measured both directly by imaging and indirectly through analysis of filament interference patterns. The stable interference pattern created by a filament pair is similar to that due to a pair of Young’s slits, and implies a constant phase relationship between the WLC generated by each filament. The experimental results agree well with theoretical predictions for the number of fringes and the fringe spacing.

Characterization of a water mist based on digital particle images

The characteristics of a water mist, such as the droplet size and velocity distribution, the water mist atomization angle and the breakup length were determined with a newly developed nonintrusive pattern method, particle image velocimetry and sizing (PIVS), which is mainly based on the manipulation of digital particle images. A series of experiments were conducted using a semiconductor laser (with wavelength 650 nm and about 35–50-mW power), a plano–convex cylindrical lens and some other lenses to produce a light sheet approximately 1-mm thick. The typical results of a water mist under different conditions are shown in this paper.

Effect of Sliding Speeds on the Friction and Wear of Pattern Abrasion of Rubber

To investigate the effect of sliding speeds on the friction and wear of pattern abrasion of rubber, rubber wheel was rubbed against a plano-convex cylindrical lens at various sliding speeds from 1 to 1000mm/s. At low speeds less than 10mm/s the linear rate of wear and coefficient of friction increased with sliding speed. They were remained almost constant between sliding speeds of 10 and 100mm/s. Beyond sliding speeds of 100mm/s, the linear rate of wear decreased rapidly by a factor of 100. The same tendencies appeared with the coefficient of friction. At that time the rubber surface was covered with a sticky material.The variations in the spacing of patterns and the spacing of striations with the sliding speeds were also studied. The spacing of patterns and the spacing of striations increased with sliding speeds at low speeds less than 10mm/s. They were almost constant between sliding speeds of 10mm/s and 100mm/s. At sliding speeds higher than 100mm/s, the spacing of patterns rapidly decreased. At that time the striations were not observed since the sticky material covered the abraded rubber surface.The linear rate of wear, though discontinuous, was proportional to the third power of the pattern spacing at sliding speeds from 1 to 1000mm/s.

Interferometric measurement of near-cylindrical surfaces with high amplitude resolution

Subaperture interferometric measurements of highly curved surfaces with a shape close to a cylinder have been performed in a normal-incident setup that consists of a Fizeau interferometer in combination with a plano-concave cylindrical lens. Since the field of view in the circumferential direction is limited by spherical aberration, the optical components were designed to minimize spherical aberration. For reference measurements a second plano-convex cylindrical lens was used. The subaperture setup leads to three-dimensional surface maps of the objects under test. To eliminate the influence of residual geometric aberrations, rectangular polynomials have been fitted and subtracted from the raw data. For deformations with spatial wavelengths below 30 mm, a rms amplitude resolution of 1 nm and a rms amplitude accuracy of 3 nm were achieved. Measurements on Wolter-type-I mirror shells are discussed in detail.

Focusing by electrical modulation of refraction in a liquid crystal cell

The creation of a field-controlled variation of the index of refraction in a liquid crystal cell has been analyzed and experimentally verified. To obtain a spherical lens utilizing a simple electrode structure and capable of focusing arbitrary incoming polarizations requires four flat nematic liquid crystal cells. With electrodes fabricated well within the current capability of photolithography, near diffraction-limited performance in terms of the optical transfer function is predicted. The focusing capability of a liquid crystal lens was demonstrated using a single cell with linear transparent electrodes. A plano-convex cylindrical lens for a single incoming polarization was thus created. While the cell had a crude electrode structure, it affirmed all the major qualitative predictions. The fringing along the edge of the electrodes required for eventually obtaining near diffraction-limited performance was observed.

A cylindrical lens for a high power transmitting array in a sector scanning sonar

The design of a plano-convex cylindrical acoustic lens, which is used in conjunction with a plane array of PZT-4 elements to provide a high power, wide beam sonar projector is outlined. Test results are detailed and compared to those computed from simple theoretical considerations.

A portable string galvanometer for use at moderate frequencies

The instrument described has been designed for use in a portable apparatus. The string galvanometer has been constructed with a frequency of vibration of 150-200 per sec. In order to secure critical damping the string is arranged in an oil-filled case, and to maintain proportionality between deflection and current the string is supported at the ends by springs. With this arrangement the deflection is proportional to the current over the whole working range, and with a magnification of 60-80 photographic records can be obtained with the light from an 18-watt 6-volt lamp, the battery for which is easily transportable. The optical system consists of a low-power microscope objective and eyepiece, and is fitted with a double convex lens and a plano-convex cylindrical lens to obtain a sharp image. The motion of the string is recorded by a film camera. The motor for moving the film is spring driven and a spring-driven time marker is also fitted. In order to identify records a device is fitted for marking notches on the edge of the film. After exposure the film is coiled up in a cylindrical box, a spring-operated knife cutting off the film when the lid of the camera is opened, to enable the film box to be removed.

II. On the spectra of some of the fixed stars

After a few introductory remarks, the authors describe the apparatu which they employ, and their general method of observing the spectra the fixed stars and planets. The spectroscope contrived for these inqu ries was attached to the eye end of a refracting telescope of 10 feet foe length, with an 8-incli achromatic object-glass, the whole mounted equa torially and carried by a clock-movement. In the construction of th spectroscope, a plano-convex cylindrical lens, of 14 inches focal length, wa employed to convert the image of the star into a narrow line of light which was made to fall upon a very fine slit, behind which was placed an achromatic collimating lens. The dispersing portion of the arrangement consisted of two dense flint-glass prisms; and the spectrum was viewe through a small achromatic telescope with a magnifying power of between 5 and 6 diameters. Angular measures of the different parts of the spectrum were obtained by means of a micrometric screw, by which the position of the small telescope was regulated. A reflecting prism was placed over one half of the slit of the spectroscope, and by means of a mirror, suitably adjusted, the spectra of comparison were viewed simultaneously with the stellar spectra. This light was usually obtained from the in­duction spark taken between electrodes of different metals. The dispersive power of the apparatus was sufficient to enable the observer to see the line Ni of Kirchhoff between the two solar lines D ; and the three constituents of the magnesium group at b are divided still more evidently*. Minute details of the methods adopted for testing the exact coincidence of the corresponding metallic lines with those of the solar and lunar spectrum, are given, and the authors then proceed to give the results of their obser­vations.