Terahertz vector vortex quantum cascade laser and preparation method thereof

Abstract

The invention relates to a terahertz vector vortex quantum cascade laser which comprises a substrate and a bonding metal layer located on the substrate, and a seed laser area and a bus waveguide which are arranged in the length direction of the laser and connected with each other are arranged on the bonding metal layer. One side of the bus waveguide is provided with a resonant ring and a transition electrode which are arranged along the length direction of the laser and are separated from each other, a metal air bridge is erected between the resonant ring and the transition electrode, and the end part of the seed laser area and the end part of the bus waveguide are provided with absorption boundaries. The invention also provides a preparation method of the terahertz vector vortex quantum cascade laser, the terahertz vector vortex laser with relatively high mode purity can be directly emitted, hollow annular far-field light spots can be realized, the emitted vector vortex light can be decomposed into left-handed and right-handed circularly polarized light carrying orbital angular momentum, the polarization characteristic is angular polarization, and the advantages of high stability, high excitation efficiency, narrow line width and high side-mode suppression ratio are achieved.

Description

technical field [0001] The invention relates to the field of terahertz quantum cascade lasers, in particular to a terahertz vector vortex quantum cascade laser and a preparation method thereof. Background technique [0002] Terahertz (THz) quantum cascade laser (quantum cascade laser, QCL) has become a coherent light source with great potential in the range of 2-5THz because of its high energy conversion efficiency, small size, easy integration, and electric pumping. It has important applications in fields such as material detection and communication. For example, in terms of imaging and material detection, because the intrinsic vibrational energy levels of a large number of molecules and clusters are in the terahertz band, this band is also called the fingerprint band of molecules. The terahertz imaging technology using this characteristic has been It is used in the fields of molecular spectroscopy, biomedicine, safety and non-destructive inspection. In terms of communica...

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Problems solved by technology

[0004] At present, vortex light is mostly generated by discrete devices, which has the disadvantage of unstable optical path assistance

The integrated vortex light emitters are all concentrated in the visible light and communication bands, and there is no laser that can directly generate vortex light in the terahertz band.

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