Ultra-small near-infrared multi-wavelength light source using a heterojunction photonic crystal waveguide and self-assembled InAs quantum dots

Abstract

We herein propose and verify an ultra-small near-infrared (NIR) multi-wavelength light source using a heterojunction photonic crystal waveguide (PC-WG) and quantum dots (QDs). A heterojunction two-dimensional PC-WG, which consists of multiple PC-WGs with sequentially shifted structural parameters, is fabricated on a GaAs-slab including InAs QDs. Spontaneous emission (SE) from embedded InAs QDs was enhanced at multiple wavelengths resonating with slow-light regions of the PC-WG modes. The enhanced SE was propagated and detected through the heterojunction PC-WG. These results indicate the feasibility of the proposed light source.

Proposal and numerical verification of an ultrasmall terahertz source using integrated photonic crystal waveguides for highly efficient differential frequency generation

“…For practical fabrication of the THz source, light-emitting materials in STD PhC-WG1 and 2 can be realized by embedding quantum wells or dots in the semiconductor slab, as we previously demonstrated. 23,28,29) In addition, the selective-area growth technique developed for integrated PhC-WGs 30,31) can be applied to the heterostructure to avoid reabsorption of the fundamental light in LVLD PhC-WG. Using these techniques, highly efficient DFG-THz sources based on integrated PhC-WGs with ultrasmall footprints may be feasible.…”

“…In addition, the shift of the STD PhC-WG1 band to a shorter wavelength than that of the STD PhC-WG2 band enables the fundamental light coupling to the photonic band in the next PhC-WG to the right, whereas it cannot be coupled to the other direction, owing to the absence of optical modes in that direction. 23) Therefore, the coupling efficiency of fundamental light in the LVLD PhC-WG can be increased.…”

“…[20][21][22] Furthermore, the line defect mode in the photonic bandgap provides a unique dispersion relation that can be controlled by the structural parameters of air holes. 23) We performed structural modifications of the PhC to realize a low-group-velocity and low-dispersion (LVLD) waveguide mode, 17,24) enabling the enhancement of the electric fields of fundamental light and satisfying their phase-matching condition. On the basis of these advantages, a highly efficient DFG of THz-wave in an LVLD PhC-WG was demonstrated.…”

2D auxetic metamaterials with tuneable micro-/nanoscale apertures

“…Depending on the geometric complexity, dimensionality, scale, resolution and material requirements of the micro-/nanostructure in question, a variety of advanced fabrication techniques may be used nowadays to produce small scale architecture systems [1,2]. These include a wide range of stereolithography methods [3][4][5][6], droplet deposition systems [7], self-assembly macromolecules [8,9] and vat photopolymerization [10,11] techniques amongst others.…”

Numerical investigation of highly efficient and tunable terahertz-wave generation using a low-group-velocity and low-dispersion two-dimensional GaAs photonic crystal waveguide

“…We previously proposed a NIR multi-wavelength emitting light source by combining self-assembled QDs and PhC-WGs. 34,35) The self-assembled QD ensemble, which is a broadband NIR light-emitting material, can be applied to a multi-wavelength laser, 36) and the frequency difference of the lasers can be used for DFG-THz-wave generation. This could be used as an all-in-one THz light source based on a common PhC-WG-based integrated device.…”