Chien-Yao Huang

Fabrication of a double-sided micro-lens array by a glass molding technique

In recent years, micro-lens arrays (MLAs) have become important elements of optical systems. One function of MLAs is to create a uniform intensity of light. Compared with one-sided MLAs, the uniformity of light intensity increases with double-sided MLAs. MLAs fabricated by glass can be used in higher temperature environments or in high-energy systems. Glass-based MLAs can be fabricated by laser machining, photolithography, precision diamond grinding process and precision glass molding (PGM) technologies, but laser machining, photolithography and precision diamond grinding process technologies are not the perfect approach for mass production. Therefore, this paper proposes a method to fabricate a mold by laser micro-machining and a double-sided MLA by a PGM process. First, a micro-hole array was fabricated on the surface of a silicon carbide mold. A double-sided MLA using two molds was then formed by a PGM process. In this paper, the PGM process parameters including molding temperature and molding force are discussed. Moreover, the profile of a double-sided MLA is discussed. Finally, a double-sided MLA with a diameter of 20 mm, and lenses with a height of 52 µm, a radius of 851 µm and a pitch of 700 µm were formed on glass.

Fabrication of a hybrid optical micro-component with a thermosetting polymer and glass

This research develops a precise hybrid optical micro-component (PHOMC) that includes polymer and glass materials. Although glass offers better anti-thermal, anti-environmental, anti-scraped, anti-corrosive, and optical properties than polymer materials do, glass materials are difficult to fabricate for microstructures. This research describes the fabrication of a PHOMC, which retains the advantages of glass materials; in addition, the cost of microstructure polymers is lower than for glass. In this study, polymers with micro sine waves can change the spot light intensity from a Gaussian distribution to a line with uniform distribution. The glass base can protect the PHOMC to avoid damage from the environment. First, the sine wave was designed using optical design software to change the light profile. A precise diamond-turning technique was used to fabricate a mold with a sine-wave profile. A glass plate was used for the base of the PHOMC. During the heating process, a thermosetting polymer was formed to match the sine-wave profile, and covered the glass base. The PHOMC is 10 mm in diameter, and a sine wave with 100 μm in amplitude and 6.283 in angular frequency was obtained. The surface profile of the PHOMC was evaluated using an ultra-precise laser confocal microscope. Processing parameters, such as the forming temperature, are discussed in this paper. The PHOMC with the sine wave that was developed in this study can generate a reference straight line for use in alignment, machine vision systems, construction, and process control.