scholarly journals Novel optical lens design with a light scattering freeform inner surface for LED down light illumination

2015 ◽  
Vol 23 (13) ◽  
pp. 16715 ◽  
Author(s):  
Raychiy J. Lin ◽  
Ming-Shiou Tsai ◽  
Ching-Cherng Sun
Keyword(s):  
Light Scattering ◽  
Light Illumination ◽  
Lens Design ◽  
Optical Lens ◽  
Inner Surface

Secondary Optical Lens Design for LED to Achieve Angular Deflection

2017 ◽  
Vol 54 (2) ◽  
pp. 022204
Author(s):  
曾赤良 Zeng Chiliang ◽  
廖文哲 Liao Wenzhe
Keyword(s):  
Lens Design ◽  
Optical Lens ◽  
Angular Deflection

scholarly journals Preliminary of Optical Lens Design for Micro-Satellite

2017 ◽  
Vol 54 ◽  
pp. 012095 ◽  
Author(s):  
Elvira Rachim ◽  
Andi Mukhtar Tahir ◽  
Agus Herawan
Keyword(s):  
Lens Design ◽  
Optical Lens

Particle Detection for 100-nm Patterned Wafers by Evanescent Light Illumination – Analysis of Evanescent Light Scattering Using Finite-Difference Time-Domain Method –

2006 ◽  
Vol 18 (6) ◽  
pp. 705-713
Author(s):  
Toshie Yoshioka ◽  
◽  
Takashi Miyoshi ◽  
Yasuhiro Takaya
Keyword(s):  
Light Scattering ◽  
Finite Difference ◽  
Time Domain ◽  
Finite Difference Time Domain ◽  
Wafer Surface ◽  
Light Illumination ◽  
Particle Detection ◽  
Wafer Inspection ◽  
Evanescent Light ◽  
Difference Time

Patterned wafer inspection technique is essential to high productivity and reliability in high-yield semiconductor manufacturing. Since circuit features are below 100nm, conventional imaging and light scattering methods cannot be applied to patterned wafer inspection technique due to the diffraction limit and the low S/N ratio. We propose a new particle detection method using annular evanescent light illumination. In this method, a converging annular beam used as a light source is incident to a micro-hemispherical lens. When the converging angle is greater than the critical angle, annular evanescent light is generated on the bottom surface of the hemispherical lens. Evanescent light is localized near the bottom of the hemispherical lens and decays exponentially away from it, so the evanescent light selectively illuminates a particle on the patterned wafer surface because it cannot illuminate the patterned wafer surface. The proposed method evaluates a particle on a patterned wafer surface by detecting scattered evanescent light pattern from the particle. To analyze the fundamental properties of the proposed method, the computer simulation was performed using the finite-difference time-domain (FDTD) method. It is found that the proposed method is effective for detecting 100nm sized particle on a patterned wafer consisting of 100nm lines and spaces, when the evanescent light illumination is done using P-polarized light and line orientation parallel to the incident plane. Finally, the experimental results suggest that 220nm sized particle can be detected on a patterned wafer consisting of about 200nm lines and spaces.

A freeform collimator lens design for the Natural Light Illumination System

2019 ◽  
Vol 52 (1) ◽  
pp. 141-150
Author(s):  
W-C Tseng ◽  
AJ-W Whang ◽  
Y-Y Chen ◽  
J-Z Chen ◽  
T-H Yang ◽  
...  
Keyword(s):  
Total Internal Reflection ◽  
Transmission Efficiency ◽  
Luminous Flux ◽  
Optical Simulation ◽  
Light Illumination ◽  
Natural Light ◽  
Lens Design ◽  
Optical Efficiency ◽  
Freeform Surfaces ◽  
Illumination System

This paper presents the design of a collimator lens for use with the Lightbrick that uses total internal reflection as well as convex and concave surfaces. The Lightbrick is a light collector for the Natural Light Illumination System. The collimator lens is constructed using freeform surfaces which can be calculated through geometric-optics. Verified by optical simulation, using the collimator lens can achieve 90.3% luminous flux within ±2°, and optical efficiency improves by 48% in the collimator lens output. The collimator lens converges the light distribution of the Lightbrick and enhances the transmission efficiency of the Natural Light Illumination System.

Strategies for Improving the Assessment of Dental Fluorosis: Focus on Optical Techniques

1994 ◽  
Vol 8 (1) ◽  
pp. 75-79 ◽  
Author(s):  
B. Angmar-Månsson ◽  
E. De Josselin de Jong ◽  
F. Sundström ◽  
J.J. Ten Bosch
Keyword(s):  
Light Scattering ◽  
Dental Fluorosis ◽  
Ccd Camera ◽  
Laser Fluorescence ◽  
Optical Methods ◽  
Light Illumination ◽  
Initial Caries ◽  
A Charge ◽  
Caries Lesions

In its milder forms, enamel fluorosis is characterized clinically by diffuse opacities. The appearance is due to optical properties of a subsurface or surface porous layer with lower mineral content. These areas usually have texture and color similar to those of initial caries lesions but generally another shape and location. Therefore, several optical methods, previously used to diagnose initial caries lesions, were applied to fluoride-induced opacities on extracted premolars and on incisors of four subjects in vivo. These methods included light-scattering measurements, white light illumination, violet light illumination, ultraviolet illumination, and laser fluorescence. Video images were captured with a charge-coupled-device (CCD) camera, digitized, and computer-processed. It is concluded that the light-scattering monitor can be used for the determination of the local porosity of fluorotic enamel and that the laser fluorescence method might be developed into a method applicable for the assessment of the severity of enamel fluorosis.

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