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The size of the optical zoom system is important in smartphone camera design, especially as it governs the thickness of the smartphone. We present the optical design of a miniaturized 10× periscope zoom lens for smartphones. To achieve the desired level of miniaturization, the conventional zoom lens can be replaced with a periscope zoom lens. In addition to this change in the optical design, the quality of the optical glass, which also affects the performance of the lens, must be considered. With advancements in the optical glass manufacturing process, aspheric lenses are becoming more widely used. In this study, aspheric lenses are incorporated into a design for a 10× optical zoom lens with a lens thickness of less than 6.5 mm and an eight-megapixel image sensor. Furthermore, tolerance analysis is carried out to prove its manufacturability.

We present a design for a cost-effective low-beam automotive headlamp with a single light-emitting diode (LED) light source. The proposed design consists of a white LED, an elliptical reflector, a parabolic reflector, a toric lens, a filter, and a prism array. The white LED had a luminous flux of 146 lm. Non-sequential rays were used to improve the efficiency and a toric lens was employed to optimize the light pattern on a 25 m screen which appeared as rectangular with a high degree of uniformity. In addition, the filter and the prism array were modified to correct the measured light pattern results to meet the requirements of ECE R112. We set the reflectivity of the elliptical and parabolic reflectors for the compound reflectors to be 95%. The transmittance of each surface of the toric lens is 98%. The total received lumens was 80.62 lm, and the overall efficiency was 55.22%.

We present an optical design for the lens depth of a periscope-type 3 × zoom lens with 8-megapixel sensor in mobile phone. In the practice application, the lens depth of zoom lens must be less than the thickness of the mobile phone mechanism. The lens depth is thus the upper size limit of the prism thickness or the maximum surface aperture in the Y-direction of the zoom lens. The zoom lens in the designed system has an F-number of F/3.5 to F/5.5, a focal length of 4.514 mm to 13.442 mm, the half field angle in the x-direction is 23.96° to 8.488°, and the half field angle in the y-direction is 14.035° to 4.798°. The smallest lens depth of the zoom lens is 5.377 mm. These results show that the depth of a periscope-type zoom lens can be embedded in the mobile phone.

This paper presents a high efficiency design of an asymmetric condenser uniform lighting system for a digital micro-mirror device (DMD) projector and compares it with a traditional collimator system and symmetrical condenser system. The optical Etendue, efficiency and uniformity of three different lighting systems used for a DMD projector were analyzed by optical simulation approach. The design results show that the optical efficiency of the asymmetric condenser system is better than the other two systems. The proposed asymmetric condenser system design significantly improves the optical efficiency of the symmetrical condenser system from 42.35%–56.13 %.

We present an optimization design for a stereo-photographic system where achromatic double-prism arrays are used in front of the camera lens to reduce chromatic aberration and distortion. Due to the optical properties of the prism, the image formed by a single-prism array exhibits large chromatic aberration and distortion. The chromatic aberration and distortion for both single-prism array and double-prism array stereo-photographic systems were analyzed by the CODE V software. The double-prism arrays have larger distortion, but the chromatic aberration is small. The distortion arising from the double-prism arrays can be compensated by the camera lens design. The design results show that the maximum spot size is reduced from 17.7 μm to 8.8 μm after optimization. The proposed stereo-photographic system has high-quality stereo images.

The luminous properties of red, green, and yellow phosphors with a blue LED are evaluated and a corresponding optical model is constructed using the optical simulation software LightTools®. According to the phosphor particle model, the desired chromaticity coordinate of the multicomponent light which is excited by a blue LED can be achieved by modifying the weight concentration of the phosphors. A comparison of the four types of LED package modules tested shows that the yellow phosphor encapsulated with a semispherical module takes up a lesser percentage of the total weight percentage of a constructed white light with a correlated color temperature of around 4000 K. The simulation and experimental results provide a cross-reference for better packaging and encapsulating designs for lumen improvement.

A newly designed non-telecentric projection zoom lens is proposed for a mini-projector with LED light sources. The projection lens consists of six spherical lenses. The zoom ratio of the projection lens is 1.1. At the wide condition, the working F/# can maintain at 2.4 and the throw ratio can operate at 1.23. The root mean square (RMS) spot sizes of all fields are smaller than 15 μm for all zoom ranges. The optical distortion and the TV distortion were suppressed to be smaller than 1.5% and 1%, respectively. For the image quality issue, the modulation transfer function (MTF) value for all fields is above 0.4 at 46 lp/mm for all zoom conditions. Even when the tolerance error was considered, the MTF value for all fields is still above 0.3 for all zoom conditions. Using this non-telecentric projection zoom lens, a very sharp image could be achieved with low cost. This low cost projection lens is very suitable for business applications.

A zoom lens design for a 10.2-megapixel digital single-lens reflex (SLR) camera with an advanced photo system type-C (APS-C) CCD image sensor is presented. The proposed zoom lens design consists of four groups of 3× zoom lenses with a focal length range of 17–51 mm. In the optimization process, 107 kinds of Schott glass combined with 26 kinds of plastic materials, as listed in Code V, are used. The best combination of glass and plastic materials is found based on the nd−Vd diagram. The modulation transfer function (MTF) was greater than 0.509 at 42 lp/mm, the lateral chromatic aberration was less than 5 μm, the optical distortion was less than 1.97%, and the relative illumination was greater than 80.05%. We also performed the tolerance analysis with the 2σ (97.7%) position selected and given tolerance tables and results for three zooming positions, which made the design more practical for manufacturing.

This paper explores lens design through thermal analysis and correction of 4-megapixel DLP projector lenses at temperatures ranging from 10°C to 80°C, and analyzes and discusses the TV distortion and lateral color with a focal length of 24 mm, F/# of 1.71, projection distance of 7.2 m, and projection screen size of 200 inches. Appropriate lens materials are selected and changes are made to the lens barrel materials to achieve athermalization. At temperatures from 10°C to 80°C, the image quality of lens is as follows: MTF (93 lp/mm) is greater than 0.554, lateral color is less than 1.39 µm, optical distortion is less than 0.147%, TV distortion is less than 0.079%, and relative illumination less than 92.52%.

The design of the LEDs lighting in general household illumination was proposed and compared with the fluorescent lighting in this study. Using the LED as a light source would promote energy saving lighting for household illumination purposes. We used the LightTools and DIALux software to design and simulate different standards of illuminance, different correlated color temperatures and different color rendering indices for household environments. The power consumption and efficiency of traditional illuminated light sources and an LED light source with the same standard of illuminance for lighting the household environment were analyzed and compared with each other. Finally, our results show the advantages of using white-light LEDs for lighting and household illumination.

We present a new detection method for an improved DVD pickup head system capable of measuring the multidirectional azimuth and small tilt angles. A complementary metal-oxide semiconductor (CMOS) sensor is used to capture images and analyze the slight shift of the central position of the beam shape when the test plane rotates to create a tilt angle and angular signal. The proposed detection method can determine the azimuth angle of the test plane from 0° to 360° at intervals of 5°. The tilt angle measurement is varied from 0° to 4.2° at intervals of 0.3°. The simulation results show that the improved DVD pickup head system can recognize multi-directional azimuth angles of the test plane under a small tilt.

An optical design with a pyramid prism array is employed to simultaneously capture four images. The apex angle design of an upper and lower prism array is to form the upper and the lower images of the object. The design of the left and right prism array is to develop the left and right images. In the prism array, the unwanted image can be eliminated by blacken process in the plane gap between each prism. The optical design was based on the pyramid prism array and a single-lens to make the system light, portable and low-cost.

A low-cost optimal double-prism method is proposed by using the developed MATLAB program to correct chromatic aberration. We present an efficient approach to choose a couple of low-cost glasses to obtain a low aberration double prism. The doublet prisms were made of two lead-free glasses. The relative partial dispersion of the two lead-free glasses is identical and their Abbe numbers are different greatly. The proposed design aims to minimize chromatic aberration, such as in apochromats, for paraxial ray tracing. Finally, an optimization design for real ray tracing can be evaluated by the chromatic aberration curve with a minimal area.

This paper presents a periscope type 3X zoom lenses design for a five megapixel cellphone camera. The configuration of optical system uses the right angle prism in front of the zoom lenses to change the optical path rotated by a 90° angle resulting in the zoom lenses length of 6 mm. The zoom lenses can be embedded in mobile phone with a thickness of 6 mm. The zoom lenses have three groups with six elements. The half field of view is varied from 30° to 10.89°, the effective focal length is adjusted from 3.142 mm to 9.426 mm, and the F-number is changed from 2.8 to 5.13.

Generally, mobile phone use one camera to catch the image, and it is hard to get stereo image pair. Adding a biprism array can help that get the image pair easily. So users can use their mobile phone to catch the stereo image anywhere by adding a biprism array, and if they want to get a normal image just remove it. Using biprism arrays will induce chromatic aberration. Therefore, we design a double biprism arrays to reduce chromatic aberration.

This paper presents a new thin-film liquid salinity sensor by using the D-shaped fiber and thin-film coating techniques. The D-shaped fiber will enhance optical fiber to generate an evanescent field in sensing applications. Indium-galliumzinc oxide (IGZO) films can produce high attenuation lossy mode resonance (LMR) to make high-sensitivity liquid salinity fiber sensors. IGZO thin film is prepared by a radio-frequency (RF) magnetron sputtering method. The optical fiber thickness is 67.6 μm and IGZO film thickness of 100 nm is deposited on the polished surface of the D-shaped fiber to fabricate LMR-type liquid salinity sensors. The sensitive region was immersed in different sensing liquid salinities from 0 ‰ to 100 ‰, and attempted to investigate the sensitivities of the LMR salinity sensors. The experimental results show that the highest sensitivity of the salinity sensors for the sensing NaCl solutions is 0.80 nm per salinity unit (SU).

An ultra-wide angle lens design with relative illumination analysis is presented. The half field angle of 80°, the relative illumination of the image plane will be reduced. It is necessary to increase the image numerical aperture ratio for X and Y direction, and decrease the angle between the chief ray and optical axis in the image space. However the ultra-wide angle lens induces great barrel distortion causing image extrusion. Therefore, we use F-theta distortion to replace optical distortion. Seven lenses and two pieces of flat glass are used for a sensor 1/6” sensor with 2.1 million pixels. The final result for the lens is a half viewing angle of 80°, F/2.4, a focal length 1.1 mm, a length of 22.37 mm, F-theta distortion of less than 2%, and relative illumination greater than 83%.

Based on the image payload on an Unmanned Aircraft System, this study utilizes a micro-prism array and single-lens remote camera to assess the feasibility of having two virtual cameras shoot terrain image pairs with inclined ±10°. The software, LightTools, is applied for simulating and verifying the feasibility of the optical system. In comparison with traditional frame-type remote cameras, this study not only could acquire highly overlapped stereoscopic image pairs from different viewing angles, but could also increase the stereoscopic image pairs by two times. The system we propose obtains more stereoscopic digital terrain information than do traditional systems.

We present a compact design for a unitary photo detector and single-path combination optical pickup head (OPH) which can be used for Blu-ray Disc, digital versatile disc and compact disc systems. The number of components in the OPH design can be reduced by focusing three discrete wavelength laser beams on the photo detector. The three laser diode chips and a photo detector can be encapsulated within an integrated optical unit (IOU), which is then combined with a compensator and rhomboid beam-splitter prism. The blazed holographic optical elements (HOEs) are designed for concentrating the diffracted light power to the 0th-order and the 1st-order to improve the round-trip efficiency. The simulation results, including the S-curve and optical efficiency, are compared for this combo-OPH with three IOUs. The optical efficiency of the proposed OPH for BD/DVD/CD systems as detected by the photo detector are 5.545%, 3.889%, and 3.517%, respectively. Our design results show that the combo-OPH with one IOU is better than the combo-OPH with three IOUs.

The converted solar energy of sunlight in the LED hybrid light box lighting system for indoor lighting is simulated and computed in this study. Sunlight is collected by a concentrator and split into visible and non-visible rays by a beam splitter. The visible rays pass through a light guide into a light box where they are mixed uniformly with the LED light, to provide uniform illumination. The non-visible rays are absorbed by a photovoltaic device to provide the electricity. We calculate the converted solar energy for our light box design and find that the energy saving is 2.6 times more than the power consumption of our indoor lighting.

We present an optical system design for determining the tilt angle and displacement of the test plane. The proposed optical system consists of a Blu-ray pickup head and a pigtailed laser diode with a uniform Gaussian beam. The optical system is evaluated by two optical design software packages, Code V and LightTools. A quadrant detector is used to detect the relative relationship of the V A , V B , V C and V D output signals, which can be used to measure the tilt angle and displacement on the test plane. Both the tilt angle and displacement on the test plane can be determined from the change in the beam shape on the quadrant detector. The proposed system can generate a circular uniform beam shape to reduce the misjudgment and to enhance the measurement accuracy. Various simulation cases are presented in detail to show the feasibility of the proposed system.

We present an optical design for Blu-ray pickup head that can synchronously detect a linear displacement and two-dimensional (2D) angular tilt of the test plane. In order to enhance the accuracy of tilt angle and discriminate more tilted orientations, a high resolution detector (177 × 177 pixels) is used as the photo detector of the Blu-ray pickup head. The horizontal beam expander is used to make the laser beam be more uniform to improve the accuracy of signal at the photo detector. The signal at the high resolution detector of the pickup head used astigmatic detection is comprised of two displacement signals and one angular signal. The displacement of the test plane is ascertained from the rate of change in the length of semi-major and semi-minor axis for elliptical beam shape on the high resolution detector. The tilt of the test plane is obtained from the brightest position of beam shape. It is not only able to judge the tilt angle for four orientations (α, β, 45°and 135°), but also the tilt angle for four orientations (30°, 60°, 120°and 150°). The smaller pixel size will help to improve the accuracy in the 2D angle measurement further.

A method for simulating the sunlight color temperature, hues and brightness immediately by adjusting the intensity of RGB LEDs in indoor lighting was proposed. Illuminating uniform with the light box, the ratio of RGB intensity could be found and calculated by measuring the CIE chromaticity coordinate x and y with chroma meter. After the chromaticity coordinate x and y was found by the chroma meter, the tristimulus values XYZ could be calculated with the chromaticity coordinate, and then transferred to RGB primaries by a linear transformation. When getting the ratio of RGB intensity, the outdoor sunlight color temperature, hues and brightness could be rebuilt by adjusting the ratio of RGB LEDs. It provides a sunlight alike lighting in indoor environment, especially for those indoor spaces that don’t have any windows to receive the sunlight.

The advantage of the LEDs illumination in general household lighting was proposed. High efficiency white LED as the light source was provided the energy saving illumination of the general household lightings. Different spaces in general household with different standards of average illuminance were designed and simulated by LightTools and DIALux software. The power consumptions and efficiency of traditional illuminated light sources and LED light source in lighting the household environment were analyzed and compared with each other at the same standard of average illuminance. Finally, it provided the advantage of using white LEDs in different spaces of the general household lighting.

A novel design of triple-wavelength design for a compact optical pickup head is presented here. We propose the use of two rhomboid beam-splitter prisms for HD-DVD, DVD and CD devices to align signals with three different wavelengths on the same optical axis. The light is collimated by a collimating lens. The parallel beams are incident on the wavelength selector. The wavelength selector separates the wavelengths with different numerical apertures. The different wavelength signals are focused on the disc by an objective lens.

An optical design for a new white LED motorcycle headlamp is presented. The motorcycle headlamp designed in this study comprises a white LED module, an elliptical reflector, a parabolic reflector, and a toric lens. The light emitted from the white LED module is located at the first focal point of the elliptical reflector and focuses on the second focal point. The second focal point of the elliptical reflector and the focal point of the parabolic reflector are confocal. We use nonsequential rays to improve the optical efficiency of the compound reflectors. The toric spherical lens allows the device to meet the Economic Commission of Europe, regulation no. 113 (ECE R113). Furthermore, good uniformity is obtained by using aspherical surface optimization of the same toric lens. The reflectivity of the reflector is 95%, and the transmittance of each lens surface is 98%. The average deviation of the high beam is 14.17%, and the optical efficiency is 66.45%.

The motorcycle headlamp is composed of a white LED module, an elliptical reflector, a parabolic reflector and a toric lens. We use non-sequential ray to improve the optical efficiency of the compound reflectors. Using the toric lens can meet ECE_113 regulation and obtain a good uniformity.

This study proposes a new simulation design for a wearable see-through retinal projector combined with a compact camera. The see-through retinal projector is composed of an illumination system and eyepiece system. In this eyeglass-mounted design, all the information is projected directly into the user's eyes using a see-through retinal projector. The retinal projector forms a 20 in. (50.8 cm) upright virtual image located 2 m in front of the human eye, and the illumination system provides uniform illumination for liquid crystal on silicon (LCoS) panels. Moreover, an RGB LED array is used as the light source to generate color images with color sequences. The compact camera has a lens with an aperture of F/2.8, a half field-of-view (FOV) of 30°, and 2 million pixels. This optical system design with the combination of a see-through retinal projector and a compact camera has a volume of about 5.83 cm(3) and a weight of 6.02 g.

We present a triple-wavelength design for a compact optical pickup head which uses two rhomboid prisms in parallel with three laser diodes. The design can be used for compact disk, digital versatile disk and high-density digital versatile disk devices. The specific prism lens used decreases the geometrical size and reduces the total number of optical components. The trade-off between tolerance and fabrication is also presented.

A novel design of HD–DVD optical pick-up head is proposed. The geometrical size of the pick-up head is reduced by using a combined system of a Penta prism and an aspherical lens. Such a combined system can replace the mirror and collimating lens in a conventional pick-up head, to achieve a miniature HD–DVD pick-up head.

We have derived a series of shape-dependent third-order aberration equations involving lens thickness. These equations are used in a simple and direct method to correct real aberrations and to find the minimum aberration for triple design that has been proposed. These calculated third-order aberrations can exactly meet the target values for each stage by means of the damped least-squares method. The shape of the three elements permits the control of three third-order aberrations: spherical aberration, coma and astigmatism. The spherical aberration is targeted first. The minimal value of the real on-axis aberration is obtained. Similarly, the coma and astigmatism target values are adjusted so as to force the full field angle real off-axis aberrations down to a minimum. Finally, the manual adjustment of the lens thickness and air spacing is used to attain the minimum aberration at the 0.7 field angle. To verify the method, two triplet design examples are presented.

An improved optimization method is presented for doublet design using the shape factor of the third-order aberrations of a thick lens to compensate high-order aberrations. This method can effectively evaluate a minimal area of aberration curves bounded by the ray-fan diagram. For the proposed optimization program, taking the RMS value of the spot diagram to be less than the diffraction limited value of the point spread function (PSF) as the evaluated criterion is suggested. The design specifications for the optimized doublet are F/3.333 and semi-field angle of 1°, within the visible spectral range. Two design examples of the doublet, one a glass lens and the other a plastic lens, are presented. The results show well-designed doublets when compared with Kingslake's design.

We simulate and compare the illuminance, uniformity, and efficiency of metal-halide lamps, white LED light sources, and hybrid light box designs combining sunlight and white LED lighting used for indoor basketball court illumination. According to the optical simulation results and our examination of real situations, we find that hybrid light box designs combining sunlight and white LEDs do perform better than either metal-halide lamps or white LED lights. An evaluation of the sunlight concentrator system used in our inverted solar cell shows that the energy consumption of stadium lighting can be reduced significantly.

The aim of this study is to design a compact LED projector that is divided into two systems: an illumination system and an imaging optical system. The illumination system consists of an RGB LED light source with a collimator lens group and a mirror with a color filter and a lens array integrator instead of an integrated rod so as to improve the uniformity of the light intensity. By using a new total internal reflection prism and projection lens, the whole optical engine is smaller in size and has a higher contrast ratio for image quality. The imaging optical system consists of a total of eight lenses (six spherical lenses and two aspherical lenses), for a total length of 52 mm; a tolerance analysis is conducted. Optical simulation software is used for the system analysis in order to determine the efficiency and uniformity of the light intensity. In this design, the uniformity of the screen reaches more than 82%, and the efficiency increases by more than 44%.

A new method for the measurement of internal stress and coefficient of thermal expansion of thin oxide films is presented and investigated experimentally, that combines digital phase shifting interferometry with image-processing technique to improve the accuracy of the conventional interferometric method. The change of the deflection (or curvature) of the coated substrates by the deposited film can be obtained by the phase maps. Using the Zernike polynomial fitting algorithm, a 3-D contour plot is generated from the polynomial coefficients to visualize the deformation of the thin film. Four oxide films prepared by ion beam sputter deposition with a Kaufman-type ion source are investigated for their mechanical properties. The contribution of the proposed method is to increase the sensitivity and accuracy of the temperature-dependence stress measurements.

We apply a digital camera with two prism arrays to capture a stereo image of the corrected chromatic aberration and distortion. The doublet prisms are used to correct chromatic aberration. The camera distortion with two prism arrays can be increased, and reduced by the lens optimization.

We present an asymmetric condenser with an elliptical solid angle distribution and improves system efficiency of 15.5%. The proposed system on the DMD achieves the light efficiency of 63.4% and the average deviation of 1.75%.

Methods for simulating the color temperature, hue and brightness of daylight illumination for indoor lighting simply by adjusting the intensity of red, green, and blue light emitting diodes are proposed. We obtain uniform color mixing with a light box by adjusting the ratios between the intensities of red, green and blue LEDs. The intensity can be found by measuring the CIE chromaticity coordinates (x, y) and the luminance Y of the daylight with a chroma meter. After the chromaticity coordinates (x, y) and the luminance Y are found, the tristimulus values can be calculated and then transferred to red, green, and blue primaries by linear transformation. With the correct ratio of red, green, and blue intensities, the color temperature, hues and brightness of daylight can be rebuilt by red, green, and blue light emitting diodes.

A hybrid method for using sunlight and light-emitting diode (LED) illumination powered by renewable solar energy for indoor lighting is simulated and presented in this study. We can illuminate an indoor space and collect the solar energy using an optical switching system. When the system is turned off, the full spectrum of the sunlight is concentrated by a concentrator, to be absorbed by solar photovoltaic devices that provide the electricity to power the LEDs. When the system is turned on, the sunlight collected by the concentrator is split into visible and non-visible rays by a beam splitter. The visible rays pass through the light guide into a light box where it is mixed with LED light to ultimately provide uniform illumination by a diffuser. The non-visible rays are absorbed by the solar photovoltaic devices to provide electrical power for the LEDs. Simulation results show that the efficiency of the hybrid sunlight/LED illumination with the renewable solar energy saving design is better than that of LED and traditional lighting systems.

We present an illustrating method for triplet prisms combination that can minimize the chromatic aberration. The apochromatic aberration equation, relation between relative partial dispersion and glass V-number can be quickly analyzed and found the combination.