Spatial coherence of electrically pumped random terahertz lasers

作     者：Eva A.A.Pogna Alessandra Di Gaspare Kimberly Reichel Chiara Liberatore Harvey E.Beere David A.Ritchie Miriam S.Vitiello EVA A.A.POGNA;ALESSANDRA DI GASPARE;KIMBERLY REICHEL;CHIARA LIBERATORE;HARVEY E.BEERE;DAVID A.RITCHIE;MIRIAM S.VITIELLO

作者机构：NESTCNR-Istituto Nanoscienze-Scuola Normale Superiore56127 PisaItaly Cavendish LaboratoryUniversity of CambridgeCambridge CB3 OHEUK 

出 版 物：《Photonics Research》 (光子学研究（英文版）)

年 卷 期：2022年第10卷第2期

页      面：524-534页

核心收录：

学科分类：0809[工学-电子科学与技术（可授工学、理学学位）] 08[工学] 0803[工学-光学工程] 0702[理学-物理学] 

基　　金：European Research Council (681379)。 

主　　题：pumped random quantum 

摘      要：Light sources with high radiance and tailored coherence properties are highly desirable for imaging applications in the mid-infrared and terahertz(THz) spectral regions, which host a large variety of molecular absorptions and distinctive fingerprints to be exploited for sensing and tomography. Here, we characterize the spatial coherence of random multimode THz quantum cascade lasers(QCLs) emitting m W optical power per mode and showing low divergence(10°–30°), performing a modified Young’s double-slit experiment. Partial spatial coherence values ranging between 0.16 and 0.34 are retrieved, depending on the specific degree of disorder. These values are significantly lower than those(0.82) of conventional Fabry–Perot THz QCLs exploiting an identical active region quantum design. We then incorporate the devised low spatial coherence random lasers into a confocal imaging system with micrometer spatial resolution and demonstrate notable imaging performances, at THz frequencies,against spatial cross talk and speckles.