In the field of vehicle lighting, due to the diode laser, its small size and high energy conversion efficiency, it can be effectively used as the headlight source of high beam. In recent years, it was adopted by European advanced car manufacturers as a new generation of automotive headlight lighting products. The current mature technology on the market is to extend the laser beam by means of reflection and to use a single high-power laser as the light source to meet the needs of surface lighting. In this research, we propose a new integrated optical design for an automotive headlight system with the rod lens, gradient-index lens (GRIN lens) and freeform lens to expand the laser beam. With regard to the diffusion of the beam by reflection and refraction, the liquid lens is used as a switch for the high beam and low beam lights to meet the needs of vehicle lighting functions and to use low-power diode lasers to synthesize the array light source. Compared with the 24-W LED headlight module available in the current market, the energy saved by this proposed optical design can increase efficiency by an average of 33%. The maximum illuminance is 56.6 lux in the high-beam mode, which is 18% higher than the standard value. Let the laser light meet the lighting requirements of regulatory standard values even beyond.

A highly efficient regular curved retroreflector is proposed to meet the requirements of the US Society of Automotive Engineers (SAE) regulations. It is demonstrated that 28% higher retroreflection efficiency and 33% more working area can be accomplished with the new designed retroreflector when compared with the commercial ones used in modern vehicles.

SiO2 particles and red-emitting CaMgSi2O6:Eu2+,Mn2+ phosphor have been added into a yellow phosphor compound YAG:Ce3+ to enhance the optical efficiency of white light LEDs whose average correlated color temperature (CCT) is in the range of 5600 K 8500 K. It was observed that altering CaMgSi2O6:Eu2+,Mn2+ concentration from 2 % to 30 % while maintaining 5 % of the SiO2 strongly influenced the color rendering index (CRI), color quality scale (CQS), and lumen efficiency of the compound. Besides, through the application of Monte Carlo simulation and Mie-scattering theory, it was possible to improve the optical properties by CaMgSi2O6:Eu2+,Mn2+ and SiO2 addition. The results provided a practical approach to achieve higher luminous efficiency and better color uniformity in remote-phosphor white LEDs (RP-WLEDs).

In fields such as biology, archeology, and industry, underwater photogrammetry can be achieved using consumer-grade equipment. However, camera operations underwater differ considerably from those on land because underwater photogrammetry involves different optical phenomena. On the basis of the requirements and specifications of the marine vessel Polaris, we developed a novel underwater camera with prime and zoom lenses and a high resolving power. The camera can be used in the spectrum in shallow water and the blue–green spectrum in deep water. In the past, ordinary cameras would be placed in waterproof airtight boxes for underwater photography. These cameras were not optimized to the underwater spectrum and environment, resulting in no breakthroughs in resolving power. Furthermore, the use of the blue spectrum greatly increases during underwater and particularly deep-water surveying. Chromatic aberration and focus-point displacement generated by the shift from the shallow-water spectrum to the blue–green spectrum in deep water makes universal underwater photography even more difficult. Our proposed optical design aimed to overcome such challenges for the development of a high-resolution underwater surveying camera. We designed a prime lens and a zoom lens. We adopted a waterproof dome window on the outer surface as the basic structure and optimized it in accordance with the conditions of different water depths and spectra to obtain distortion within ±2% and high-resolution underwater imaging quality. For the zoom lens design, we employed a genetic algorithm in Zemax to attenuate chromatic aberration as a kind of extended optimization. This novel optical design that can be used in all waters is expected to greatly reduce the volume and weight of conventional underwater cameras by more than 50% and 60%, respectively, and increase their resolving power by 30–40%.

The galvanometer scanning system plays a crucial role in modern laser material processing. With the development of this industry, the requirements for galvanometer scanners are getting higher and higher, especially to overcome the inherent disadvantages that still exist, such as image distortion, marking speed and accuracy in state-of-the-art scanning systems. In this paper, a single-axis optical scanner using two galvanometers in combination with one f-theta telecentric lens and a 343 nm femtosecond pulse laser source is proposed as a new approach for enhancing the precision of laser micromachining technology. The additional second galvanometer is used to manipulate the output laser beam of the first galvanometer to the path with less lens aberration to enhance the telecentricity correction and the effective scanning area. This is based on the international standard regulation ISO (the International Organization for Standardization) 11145:2018 requirements in optics and photonics, in which an important criterion is for the roundness of the focused beam spot to be greater than 87% to determine the effective working length of the proposed scanning system compared to the conventional scanning system. It is demonstrated by optical simulations and real optical experiments that the effective working length can be increased by 3.6 mm, corresponding to 8.1% of the effective scanning field, to achieve a laser material processing system with ISO standard. The damped least squares (DLS) algorithm in optical design software ZEMAX is used to optimize the deflected angle of the two galvanometers to obtain the optimal incident position of the f-theta lens.

To enhance driving safety at night, a new freeform-surface street light luminaire was proposed and evaluated in this study that meets the requirements of the International Commission on Illumination (CIE) M3 class standard for road lighting. The luminaire was designed using simulations to optimize the location of the bulb according to the requirements of the standard. The light source IES file was experimentally obtained for the optimized luminaire prototype with a 150 W ceramic metal halide lamp using an imaging goniophotometer. The trial road lighting simulation results computed by the lighting software DIALux indicated that the proposed luminaire provided an average road surface brightness of 1.1 cd/m² (compared to a minimum requirement of 1.0 cd/m²), a brightness uniformity of 0.41 (compared to a minimum requirement of 0.4), a longitudinal brightness uniformity of 0.64 (compared to a minimum requirement of 0.6), and a glare factor of 7.6% (compared to a maximum limit of 15%). The findings of the image goniophotometer tests were then confirmed by the results of a certified mirror goniophotometer test conducted by the Taiwan Accreditation Foundation (TAF). The results of this study can be used to provide improved street lighting designs to meet enhanced international standards.