Coatings, Vol. 13, Pages 972: Improvement of Optical Confinement for Terahertz Vertical-Cavity Surface-Emitting Laser with Square-Lattice Photonic Crystal Structure
Coatings doi: 10.3390/coatings13060972
A new method proposed to enhance the optical confinement of the terahertz band in a vertical cavity surface emitting laser involves introducing a square-lattice photonic crystal structure. This structure&rsquo;s filling factor was optimized by computing the energy band structure and optical band values of the photonic crystal. The optimal optical band value is 0.436&ndash;0.528 a/&lambda;. At a specific carrier concentration, the real part of dielectric constant of GaAs/AlGaAs materials will gradually increase with the increase of Al elements. By adjusting the length of the resonant cavity, a vertical cavity surface emitting laser with two wavelengths can be created without utilizing current injection. Additionally, the photonic crystal structure&rsquo;s control effect on the transverse mode of the vertical cavity surface emitting laser and the release effect of the PN junction light confinement were analyzed. Numerical calculations indicated that incorporating a cubic photonic crystal structure in the vertical cavity surface emitting laser resulted in a 2&times; increase in the difference frequency intensity and a 6.33&times; increase in the optical field intensity.
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