Recently, the State Key Laboratory of Strong-Field Laser Physics of Shanghai Institute of Optics and Precision Machinery (SIPM), Chinese Academy of Sciences (CAS), in collaboration with Hangzhou Institute of Advanced Studies of Chinese Academy of Sciences (HIAS) and Huazhong University of Science and Technology (HUST), has realized high-performance chalcogenide single-mode lasers at subwavelength scales based on the study of chalcogenide gain mechanism with the miniaturization of lasers as the traction. The related research results, titled Water-resistant subwavelength perovskite lasing from transparent silica-based nanocavity, were published in Advanced Materials ( Advanced Materials).
Metal halide chalcogenides are considered to be one of the ideal gain media for high-performance micro- and nano-laser devices, with potential applications in on-chip photonic information processing systems and future integrated optoelectronics. Currently, the mainstream technology for the preparation of chalcogenide lasers mainly uses the solution method. Compared with it, thermal evaporation technology is easier to achieve large-area production with controlled precision and has already been applied in commercial light-emitting diodes. However, thermally evaporated chalcogenide films have been less studied for lasers due to their high defectivity, and therefore performance lags behind their solution-treated counterparts. In addition, another challenge faced by chalcogenide lasers is that they are more sensitive to humidity, limiting the commercial application of chalcogenide-based devices, especially since little experimental work has been reported on chalcogenide lasers in water.
a, three-source co-evaporation schematic; b, chalcogenide fluorescence spectra; c, fluorescence lifetime; d-f, temperature-dependent fluorescence spectra of luminescence intensity, half-height width, and peak position plots
Progress of Shanghai Institute of Optical Machinery in the research of high-frequency and high-power ultrafast lasers at high gravimetric frequency
a-f, gain dynamics mechanism; g-i, compound dynamics mechanism
a, sub-wavelength vertical cavity laser output spectra; b, laser input-output diagram; c, laser interferogram; d, laser output spot diagram; e, underwater laser schematic; f, underwater laser output spectra; g, 20 days of underwater laser stable output
The study used a ligand-assisted three-source co-evaporation strategy to develop high-quality chalcogenide thin-film gain media by introducing additives to slow down crystallization, achieve defect passivation and domain-limited modulation. The study confirms that the optimized chalcogenide thin films have excellent carrier composite properties and enhanced optical gain performance by ultrafast transient absorption spectroscopy experiments. Inspired by the aforementioned high gain, a simple symmetric structure based on a transparent symmetric SiO2 sheet was constructed to realize a low-threshold (13 μJ/cm2) single-mode sub-wavelength-scale (120 nm) thermally evaporated chalcogenide laser, which can be operated stably and single-mode under water for more than 20 days, and its long-range coherence length (115.6 μm) and high linear polarization (82%) further confirm the excellent performance of this miniaturized laser. The long range coherence length (115.6 μm) and high linear polarization (82%) further confirm the excellence of this miniaturized laser. The combination of this compact and simple transparent vertical cavity structure and thermal evaporation process is expected to provide a simple, robust and reliable mass production strategy for future silicon photonics-compatible chalcogenide lasers, and to support the development of new types of chalcogenide optoelectronic devices with improved performance.
The research is supported by the National Key Research and Development Program of China, the National Natural Science Foundation of China, and the Shanghai Basic Research Pilot Program.
