Tapered Quantum Cascade Laser Arrays Integrated with Talbot Cavities

Abstract

Power scaling in broad area quantum cascade laser (QCL) usually leads to the deterioration of the beam quality with an emission of multiple lobes far-field pattern. In this letter, we demonstrate a tapered QCL array integrated with Talbot cavity at one side of the array. Fundamental supermode operation is achieved in the arrays with taper straight-end connected to the Talbot cavity. Lateral far-field of the fundamental supermode shows a near diffraction limited beam divergence of 2.7°. The output power of a five-element array is about three times as high as a single-ridge laser with an emission wavelength of around 4.8 μm. However, arrays with the taper-end connected to the Talbot cavity always show a high-order supermode operation whatever Talbot cavity length is.

Steering Synchronization Dynamics of Laterally Coupled Laser Array with Monolithically-Integrated External Cold Cavity

“…For instance, Meng et al implemented that integrated Zt/2 and Zt/4 fractional external Talbot cavity quantum cascade laser (QCL) array could achieve both in-phaselocking and out-of-phase-locking by different configurations [15]. Liu et al also integrated fractional external Talbot cavity into QCL array with an intracavity spatial filter, tapered QCL array and terahertz QCL array, respectively and all realized phase-locking [16][17][18].…”

Synchronization dynamics of tunable phase of monolithically-integrated external cold cavity edge-emitting laser array

“…For instance, Meng et al implemented that integrated Zt/2 and Zt/4 fractional external Talbot cavity quantum cascade laser (QCL) array could achieve both in-phaselocking and out-of-phase-locking by different configurations [15]. Liu et al also integrated fractional external Talbot cavity into QCL array with an intracavity spatial filter, tapered QCL array and terahertz QCL array, respectively and all realized phase-locking [16][17][18].…”

Constructive emission from terahertz quantum cascade laser array integrated with Talbot cavity

“…In this paper, we report on a phase-locked array scheme based on the integration of ridge array and Talbot cavity [10][11][12][13][14] in the terahertz frequency range to improve the performance of THz QCLs. By adjusting the absorption boundary width of the ridge array, the waveguide losses for high-order supermodes are significantly increased, making the Talbot devices work stably in the fundamental supermode.…”