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To promote the feasibility of using photonic crystals to enhance light extraction of light-emitting diodes (LEDs) for industrial applications, the request for the high-yield and simple exposure process to pattern two-dimensional photonic crystals (2DPCs) becomes rather urgent. In this work, we developed a one-shot three-beam laser interference system to fabricate a 2DPC on an InGaN-based green LED to address its performance for backlight display applications. Using the current exposure system we develop here, a submicro-patterned area of 6 mm in diameter can be achieved. The experimental results show that the operating voltage of a 1 times 1 mm2 in-area LED incorporated with the 2DPC is around 4 V, and the light extraction efficiency is enhanced by a factor of 2.1.

We propose and demonstrate a holographic system using three beams to generate periodic patterns for fabricating photonic crystals. By properly adjusting the incident angle and intensity of three laser beams, the period and structure of interference pattern can be modified. Computer simulation results will be presented and optical holographic system will be constructed. In addition, a simple optical inspection method for real-time examining the structure of photonic crystal will be developed. Optical experimental result will be demonstrated and discussed in this paper.

In this study, the micropore shape of two-dimensional (2D) photonic crystal structures can be modified and controlled by the intensity ratio of the incident beams of the holographic lithography. By adjusting the intensity ratio of the incident beams, the micropore shape of 2D hexagonal photonic crystal structure could be adjusted from being circular to being elliptical. Hence, we defined and analyzed the ellipticity of the micropore shape on a 2D photonic crystal structure as a function of the intensity ratio of the incident beams. In addition, we set up an optical holographic system by using three incident beams with different intensities to demonstrate the influence of the intensity ratio of the incident beams on the micropore shape. The optical experimental results show that the ellipticity of the micropore shape decreased with increasing the intensity ratio of the incident beams, which is the same trend as with the theoretical analysis.