Chinese Academy of Sciences

Soochow University

Ruiying Zhang

Shunjun Ji

Xiaoping Xu

The present invention provides a method for synthesizing a 3-spiro three-membered ring indolinone derivative, which comprises under a protective atmosphere, reacting a 3-indol-ethanol compound as a reaction raw material at 20-60° C. in the presence of an additive and an organic base in an organic solvent, to obtain a 3-spiro three-membered ring indolinone compound after the reaction is complete. The additive is N-bromosuccinimide (NBS) or N-chlorosuccinimide (NCS). The method of the present invention does not require a metal catalyst, and the 3-spiro three-membered ring indolinone derivative is synthesized in one step in the presence of NBS or NCS. The reaction conditions are mild, the operations are simple and safe, and the yield is high.

Method for synthesizing 3-spiro three-membered ring indolinone derivative

A narrow linewidth laser includes a passive ring resonant cavity, an FP resonant cavity, and a first gain region. The passive ring resonant cavity and the FP resonant cavity are combined to form an M-Z (Mach-Zehnder interference structure) compound external cavity structure, and the M-Z compound external cavity structure is at least used for providing wavelength selection and narrowing laser linewidth. The first gain region is provided on the outer side of the M-Z compound external cavity structure and is used for providing a gain for the whole laser. The narrow linewidth laser is simple in structure, high in side-mode suppression ratio, narrow in linewidth, and high in output power. By further integrating a PN junction region or MOS junction region, broadband and rapid tuning with low power consumption can also be achieved, and tuning management is simple.

Narrow linewidth laser

The present disclosure discloses a narrow-linewidth laser. The narrow-linewidth laser comprises a passive ring waveguide, a first passive input/output waveguide which is coupled with the passive ring waveguide, a gain wavelength-selection unit which is used for providing gain for the whole laser and is configured to be capable of selecting the light with a specific wavelength to be coupled into the passive ring waveguide, and a second passive input/output waveguide which is coupled with the passive ring waveguide in order to output lasing light from the laser. The narrow-linewidth semiconductor laser provided by the present disclosure has a simple structure and does not have butt-joint coupling loss between a gain region and a waveguide external cavity region. There is no a linewidth limitation caused by butt-coupling loss in such semiconductor lasers. Moreover, because of the integral formation semiconductor technique, the laser should have low cost, higher stability and reliability, and higher resistance to severe environment. Furthermore, based on a loss compensation structure, a ring external cavity of the laser can work in a critical coupling state under different coupling coefficients. Therefore, the laser with a narrow linewidth and a high side-mode suppression ratio should be achieved.

Narrow-linewidth laser

A ring cavity device includes a passive ring waveguide and an input/output waveguide horizontally coupled to the passive ring waveguide, including an active waveguide structure vertically coupled to the passive ring waveguide and/or the input/output waveguide. The active waveguide structure compensates for the loss of the passive ring waveguide. A method for fabricating a ring cavity device is also included. The ring cavity device may obtain part of the gain by vertical coupling or mixed coupling (vertical coupling followed by horizontal coupling) thus to compensate the loss in the ring cavity device. Hence, the quality factor of the ring cavity device is improved.

Growing community of inventors

Suzhou, China

Ruiying Zhang