Simultaneous ultraviolet, visible, and near-infrared continuous-wave lasing in a rare-earth-doped microcavity

Abstract

Microlaser with multiple lasing bands is critical in various applications, such as full-color display, optical communications, and computing. Here, we propose a simple and efficient method for homogeneously doping rare earth elements into a silica whispering-gallery microcavity. By this method, an Er-Yb co-doped silica microsphere cavity with the highest quality (Q) factor (exceeding 10 8 ) among the rare-earth-doped microcavities is fabricated to demonstrate simultaneous and stable lasing covering ultraviolet, visible, and near-infrared bands under room temperature and a continuous-wave pump. The thresholds of all the lasing bands are estimated to be at the submilliwatt level, where both the ultraviolet and violet continuous wave upconversion lasing from rare earth elements has not been separately demonstrated under room temperature until this work. This ultrahigh-Q doped microcavity is an excellent platform for highperformance multiband microlasers, ultrahigh-precision sensors, optical memories, and cavity-enhanced light-matter interaction studies.

Potential of Mie–Fluorescence–Raman Lidar to Profile Chlorophyll a Concentration in Inland Waters

“…ZJU-MFRL is mainly composed of three parts, namely, the transmitting system, the receiving system, and the control system (Figure b). A compact diode-pumped Nd:YAG solid-state laser is used in the transmitting system with a pulse energy of 5 mJ, a pulse width of 2.5 ns, a repetition rate of 10 Hz, and a divergence angle of 1 mrad at 532 nm. , The transmitting direction is adjusted by the reflector, the divergence angle of the laser is adjusted by the beam expander and the polarization degree is improved by the Gran laser prism after entering the atmosphere and seawater . To collect elastic scattering and chlorophyll fluorescence (ChlF) information on water, the receiving system employs three channels to collect signals, including a 532-nm Mie channel, a 650-nm Raman channel, and a 685-nm fluorescence channel, where the wavelengths are determined by optical filters.…”

Nanosecond-Pulsed Passively Q-Switched Fiber Laser by Using Photothermal Dynamics in a Dielectric Microcavity

“…Whispering-gallery-mode (WGM) optical microcavities have engaged increasing attention due to their ultrahigh quality (UHQ) factor and small mode volume ( V m ). , They have been demonstrated as a diverse platform for a wide range of applications, such as lasing, − sensing, − nonlinear optics, − and optomechanics. − The superior capability of WGM microcavities significantly enhances light–matter interactions and enables ultrahigh power density to be built up . As the light power accumulates, the increase in cavity temperature, which affects the material refractive index and the size of the microcavity, induces changes in the resonant frequency and the mode field distribution. , Hence, thermal nonlinear effects are ubiquitous in WGM microcavities and are extensively used for thermal sensing, ,, thermal locking, , thermo-optic tuning, , thermal imaging, , and thermo-optic pulsing .…”

Visible nonlinear stimulated scatterings generated in a carbon disulfide filled microbubble cavity

“…The discovery of multi-wavelength visible lasers in liquid-core fibers [7] , micro-ring cavities [8] , micro-tubular cavities [9] , micro-sphere cavities [10] , and other micro-resonant cavities have been reported. It is easier to achieve multi-wavelength lasers in microcavity using various types of dyes [11,12] or co-doped rare earth ions [13,14,15] as gain media, while it is difficult to achieve multi-wavelength laser for a single organic solution [16] .…”