Three-visible-light wave combiner based on photonic crystal microcavities

Abstract

We propose a three-visible-light wave combiner based on two-dimensional square-lattice photonic crystal (PhC) microcavities. A coupled-cavity waveguide is introduced to reduce the insertion losses for the three waves in the combiner. The transmission characteristic of light waves in PhCs with point defects is analyzed. As an example, a combiner for combining light waves of 488, 532, and 635 nm, which are commonly used as the three primary colors in laser display systems, is designed and demonstrated through the finite-difference time-domain method. The three visible light waves of 488, 532, and 635 nm are output at the same output port with transmittances of 97.6%, 98.1%, and 90.0%, respectively. The results show that the proposed device can perform efficient synthesis and the designing method can be applied in building other combiners based on PhCs made of dispersion materials.

Inverse design of an ultracompact RGB coupler with subwavelength structure

“…Furthermore, the initial structure of these designs requires the researcher to have a significant amount of design experience, which is a common issue with traditional forward design methods. As a result, miniaturization of projection devices and near-eye display devices has become an important research focus in this field 9 .…”