Noise-sidebands-free and ultra-low-RIN 1.5 μm single-frequency fiber laser towards coherent optical detection

A noise-sidebands-free and ultra-low relative intensity noise(RIN) 1.5 μm single-frequency fiber laser is demonstrated for the first time to our best knowledge. Utilizing a self-injection locking framework and a booster optical amplifier, the noise sidebands with relative amplitudes as high as 20 dB are completely suppressed.The RIN is remarkably reduced by more than 64 dB at the relaxation oscillation peak to retain below-150 dB∕Hz in a frequency range from 75 kHz to 50 MHz, while the quantum noise limit is -152.9 d B∕Hz.Furthermore, a laser linewidth narrower than 600 Hz, a polarization-extinction ratio of more than 23 dB, and an optical signal-to-noise ratio of more than 73 dB are acquired simultaneously. This noise-sidebands-free and ultralow-RIN single-frequency fiber laser is highly competitive in advanced coherent light detection fields including coherent Doppler wind lidar, high-speed coherent optical communication, and precise absolute distance coherent measurement.

Multi-functional bismuth-doped bioglasses: combining bioactivity and photothermal response for bone tumor treatment and tissue repair

Treatment of large bone defects derived from bone tumor surgery is typically performed in multiple separate operations,such as hyperthermia to extinguish residual malignant cells or implanting bioactive materials to initiate apatite remineralization for tissue repair;it is very challenging to combine these functions into a material.Herein,we report the first photothermal(PT)effect in bismuth(Bi)-doped glasses.On the basis of this discovery,we have developed a new type of Bi-doped bioactive glass that integrates both functions,thus reducing the number of treatment cycles.We demonstrate that Bi-doped bioglasses(BGs)provide high PT efficiency,potentially facilitating photoinduced hyperthermia and bioactivity to allow bone tissue remineralization.The PT effect of Bi-doped BGs can be effectively controlled by managing radiative and non-radiative processes of the active Bi species by quenching photoluminescence(PL)or depolymerizing glass networks.In vitro studies demonstrate that such glasses are biocompatible to tumor and normal cells and that they can promote osteogenic cell proliferation,differentiation,and mineralization.Upon illumination with near-infrared(NIR)light,the bioglass(BG)can efficiently kill bone tumor cells,as demonstrated via in vitro and in vivo experiments.This indicates excellent potential for the integration of multiple functions within the new materials,which will aid in the development and application of novel biomaterials.

In situ instant generation of an ultrabroadband near-infrared emission center in bismuth-doped borosilicate glasses via a femtosecond laser

Bismuth(Bi)-doped photonic materials, which exhibit broadband near-infrared(NIR) luminescence(1000–1600 nm), are evolving into interesting gain media. However, the traditional methods have shown their limitations in enhancing Bi NIR emission, especially in the microregion. Consequently, the typical NIR emission has seldom been achieved in Bi-doped waveguides, which highly restricts the application of Bi-activated materials.Here, superbroadband Bi NIR emission is induced in situ instantly in the grating region by a femtosecond(fs)laser inside borosilicate glasses. A series of structural and spectroscopic characterizations are summoned to probe the generation mechanism. And we show how this novel NIR emission in the grating region can be enhanced significantly and erased reversibly. Furthermore, we successfully demonstrate Bi-activated optical waveguides.These results present new insights into Bi-doped materials and push the development of broadband waveguide amplification.

Correction:Multi-functional bismuth-doped bioglasses:combining bioactivity and photothermal response for bone tumor treatment and tissue repair

In this originally published article,we have noticed several mistakes.They should be corrected as follows:1.On page 1,the second affiliation(No.5)of the author“Chuanbin Mao”should be deleted as he does not belong to that affiliation.Namely,he should be only listed with(Department of Chemistry and Biochemistry Stephenson Life Sciences Research Center,University of Oklahoma,Norman,OK 73072,USA).