Optical Solitons: From Fibers To Photonic Crystals
Controlling light transport in nonlinear active environments is a topic of considerable interest in the field of optics. In such complex arrangements, of particular importance is to devise strategies to subdue chaotic behaviour even in the presence of gain/loss and nonlinearity, which often assume adversarial roles. Quite recently, notions of parity-time (PT) symmetry have been suggested in photonic settings as a means to enforce stable energy flow in platforms that simultaneously employ both amplification and attenuation. Here we report the experimental observation of optical solitons in PT-symmetric lattices. Unlike other non-conservative nonlinear arrangements where self-trapped states appear as fixed points in the parameter space of the governing equations, discrete PT solitons form a continuous parametric family of solutions. The possibility of synthesizing PT-symmetric saturable absorbers, where a nonlinear wave finds a lossless path through an otherwise absorptive system is also demonstrated.
Optical Solitons: From Fibers to Photonic Crystals
In photonics, PT-symmetric complex potentials can be readily implemented by symmetrically intermixing gain/loss regions in conjunction with refractive index modulation8,9,10,11,12. As shown in several studies, PT-symmetric optical arrangements can exhibit several interesting and counterintuitive properties, which are otherwise unattainable in standard configurations8,9,10,11,12,13,14,15,16,17,18,19,20,21,22. These include for example, power unfolding and breaking of the left-right symmetry8, abrupt phase transitions9,10,11,12, non-Hermitian Bloch oscillations14, simultaneous lasing-absorbing16 and selective mode lasing in microring resonator systems23,24. Moreover, unidirectional invisibility11,25,26 and defect states27 with unconventional properties have been also demonstrated. Finally, PT-symmetric concepts have also been used in plasmonics and optical metamaterials28. Lately, it has been shown that operating close to the exceptional point of a PT-symmetric coupled microring arrangement can significantly affect thermal nonlinearities and Raman lasing29. Clearly of interest would be to investigate the role of nonlinearity within the framework of PT-symmetric periodic structures and lattices.
In particular, this symposium honors Linn Mollenauer, the scientist who first demonstrated solitons in optical fiber in 1980, and one of the towering figures in optical soliton experiments. Linn, who passed away in July 2021, spent his career at Bell Laboratories until retiring in 2003. During his research tenure, he demonstrated a wide range of nonlinear optical phenomena in fibers, such as short pulse solitons, soliton lasers and the soliton self-frequency shift. 041b061a72