Working Principle (IMAGE)
Light Publishing Center, Changchun Institute of Optics, Fine Mechanics And Physics, CAS
Caption
a, Sketch of the multimode lasing from isolated microspheres (top), and RGB single-mode lasing from heterogeneously coupled microcavities (bottom), where each microsphere functions as not only the laser source but also the mode modulator for the other resonators. b, Schematic illustration of the mode selection mechanism in heterogeneously coupled system. The lasing mode (λ1) is well confined in the left resonator because of the low transmission loss introduced from filter cavity at λ1, resulting in a blue single-mode lasing action. In the same coupled system, when the right resonator serves as lasing cavity, another lasing mode (λ2) dominates the right resonator, and single-mode lasing in other gain region can be realized. With the two resonators in the heterogeneously coupled system providing different optical gains, both of them can be applied as laser cavities. Modulated by the right resonator, single-mode lasing can be achieved in the left microcavity, and vice versa. c, tunable red, green and blue single-mode lasing in three-component heterogeneously coupled system. When each individual microsphere cavity was pumped above the threshold, single-mode lasing was achieved at the corresponding wavelength. When two of the coupled microcavities were pumped above their thresholds, any light combination comprising two of the RGB single-mode lasers can be generated. Tunable multicolor single-mode lasers (B + G, G + R and B + R) was obtained by adjusting the manner of optical pump, and RGB single-mode laser was achieved when all the three microspheres were integrally pumped.
Credit
by Yuxiang Du, Chang-Ling Zou, Chunhuan Zhang, Kang Wang, Chan Qiao, Jiannian Yao, and Yong Sheng Zhao
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.