How to Measure the Optical Quality of Focussing Solar Collectors without Laser Ray Tracing

This paper describes a novel alternative to the laser ray trace technique for evaluating the optical Quality of focusing solar collectors. The new method does not require any equipment beyond that which is used for measuring collector efficiency; it could therefore become part of routine collector testing. The total optical errors resulting from imperfect specularity and from inaccuracies in reflector position or slope are characterized by an angular standard deviation σoptical, the rms deviation of the reflected rays from the design direction. The method is based on the fact that the off-axis performance of a concentrator depends on σoptical. An angular scan is performed; i.e., the collector output is measured as a function of misalignment angle over the entire range of angles for which there is measurable output (typically a few degrees). This test should be carried out on a very clear day, with the receiver close to ambient temperature (if the latter condition cannot be satisfied, appropriate corrections are necessary). The parameter σoptical is then determined by a least-squares fit between the measured and the calculated angular scan. We tested the method on a parabolic trough collector manufactured by Hexcel, and it is suitable for parabolic dishes as well.

Download Full-text

Determining the optical quality of focusing collectors without laser ray tracing

10.2172/5415024 ◽

1980 ◽

Author(s):

P. Bendt ◽

H. Gaul ◽

A. Rabl

Keyword(s):

Ray Tracing ◽

Optical Quality

Download Full-text

Vacuum deposition rate and optical quality of the As2S3 films

Scientific Herald of Uzhhorod University Series Physics ◽

10.24144/2415-8038.2015.37.89-97 ◽

2015 ◽

Vol 37 (0) ◽

pp. 89-97

Author(s):

В. М. Жихарєв ◽

В. Ю. Лоя ◽

А. М. Соломон ◽

Я. В. Грицище

Keyword(s):

Deposition Rate ◽

Optical Quality ◽

Vacuum Deposition

Download Full-text

The Effect of Transient Structural Response to Deformation on the Optical Quality of Automotive Glass

International Journal of Forming Processes ◽

10.3166/ijfp.7.487-496 ◽

2004 ◽

Vol 7 (4) ◽

pp. 487-496

Author(s):

Alejandro Bueno

Keyword(s):

Structural Response ◽

Optical Quality

Download Full-text

Faculty Opinions recommendation of The impact of glistenings on the optical quality of a hydrophobic acrylic intraocular lens.

Faculty Opinions – Post-Publication Peer Review of the Biomedical Literature ◽

10.3410/f.735586207.793562640 ◽

2019 ◽

Author(s):

Eric C Amesbury

Keyword(s):

Intraocular Lens ◽

Optical Quality ◽

The Impact ◽

Hydrophobic Acrylic

Download Full-text

Structural and Optical Properties of InAsSbBi Grown by Molecular Beam Epitaxy on Offcut GaSb Substrates

Photonics ◽

10.3390/photonics8060215 ◽

2021 ◽

Vol 8 (6) ◽

pp. 215

Author(s):

Rajeev R. Kosireddy ◽

Stephen T. Schaefer ◽

Marko S. Milosavljevic ◽

Shane R. Johnson

Keyword(s):

Molecular Beam Epitaxy ◽

Molecular Beam ◽

Optical Quality ◽

X Ray Diffraction ◽

Interface Quality ◽

Force Microscopy ◽

Atomic Force ◽

Transmission Electron ◽

Lateral Variations

Three InAsSbBi samples are grown by molecular beam epitaxy at 400 °C on GaSb substrates with three different offcuts: (100) on-axis, (100) offcut 1° toward [011], and (100) offcut 4° toward [011]. The samples are investigated using X-ray diffraction, Nomarski optical microscopy, atomic force microscopy, transmission electron microscopy, and photoluminescence spectroscopy. The InAsSbBi layers are 210 nm thick, coherently strained, and show no observable defects. The substrate offcut is not observed to influence the structural and interface quality of the samples. Each sample exhibits small lateral variations in the Bi mole fraction, with the largest variation observed in the on-axis growth. Bismuth rich surface droplet features are observed on all samples. The surface droplets are isotropic on the on-axis sample and elongated along the [011¯] step edges on the 1° and 4° offcut samples. No significant change in optical quality with offcut angle is observed.

Download Full-text

Effect of defocus combined with rotation on the optical performance of trifocal toric IOLs

European Journal of Ophthalmology ◽

10.1177/11206721211002121 ◽

2021 ◽

pp. 112067212110021

Author(s):

Javier Ruiz-Alcocer ◽

Irene Martínez-Alberquilla ◽

Amalia Lorente-Velázquez ◽

José F Alfonso ◽

David Madrid-Costa

Keyword(s):

Visual Quality ◽

Optical Quality ◽

Refractive Errors ◽

Focal Points ◽

Modulation Transfer ◽

Optical Analysis ◽

Toric Intraocular Lens ◽

Toric Iols ◽

Reference Situation

Purpose: To objectively analyze the optical quality of the FineVision Toric intraocular lens (IOL) with two cylinder powers when different combinations of rotations and residual refractive errors are induced. Methods: This study assessed the FineVision Toric IOL with two different cylinder powers: 1.5 and 3.0 diopters (D). Three different rotation positions were considered: centered, 5° and 10° rotated. An optical bench (PMTF) was used for optical analysis. The optical quality of the IOLs was calculated by the modulation transfer function (MTF) at five different focal points (0.0, 0.25, 0.50, 0.75, and 1.00 D). Results: The MTF averaged value of the reference situation was 38.58 and 37.74 for 1.5 and 3.0 D of cylinder, respectively. For the 1.5 D cylinder, the combination of 5° of rotation with a defocus of 0.25, 0.50, 0.75, and 1.0 D induced a decrease on the MTF of 12.39, 19.94, 23.43, 24.23 units, respectively. When induced rotation was 10°, the MTF decrease was 17.26, 23.40, 24.33, 24.48 units, respectively. For the 3.0 D cylinder, the combination of 5° with 0.25, 0.50, 0.75, and 1.0 D of defocus, induced a decrease on the MTF of 12.51, 18.97, 22.36, 22.48 units, respectively. When induced rotation was 10°, the MTF decrease was: 18.42, 21.57, 23.08, and 23.61 units, respectively. Conclusion: For both FineVision Toric IOLs there is a certain optical tolerance to rotations up to 5° or residual refractive errors up to 0.25 D. Situations over these limits and their combination would affect the visual quality of patients implanted with these trifocal toric IOLs.

Download Full-text