A new wavelength tunable isomerization laser using quantum dots (QDs) and silicon photonics with a large optical gain over a wavelength range of 1000 to 1300 nm is suitable for use with other active and passive components to form highly integrated photonic devices . Japan's Tohoku University in Sendai and the Tokyo Institute of Information and Communication Research (NICT) in Japan developed a new ultra-small package of new tunable wavelength laser devices. The device has a center wavelength of 1230 nm with 44 nm tuning wideband around the center. Recently developed high-capacity optical fiber transmission system using wavelength division multiplexing (WDM) dense frequency channel system. As the frequency channels in the 1530-1565 nm conventional band (C-band) are overwhelmed, the spectral efficiency of WDM systems tends to be saturated. However, more unutilized frequency resources are buried in the near-infrared (NIR) region, such as the thousand-band (T-band) at 1000-1260 nm and the original band (O-band) at 1260-1350 nm. Quantum dot-based optical gain media has a variety of attractive features including super-optical gain bandwidth, high-temperature device stability and small linewidth enhancement factors, while silicon photonic waveguide based on silicon-on-insulator (SOI) Highly integrated photonics devices. Photonic devices for short-range data transmission require smaller package sizes and lower power consumption. Therefore, a compact, low-power wavelength tunable semiconductor laser is the key to large-capacity data transmission systems. Since the system will use an undeveloped frequency band for data transmission, a tunable wavelength tunable laser diode fabricated from a quantum dot optical gain medium and a silicon photonics external cavity is the best choice for this system. Researchers used quantum dot growth technology to fabricate a quantum dot optical amplifier on a large-diameter GaAs substrate as an optical gain medium and a wavelength-tunable filter using silicon photonics. The filter is composed of ring resonators of different sizes, which make the quantum dot optical amplifier only reflect the light with a specific wavelength through the vernier effect. Finally, a stepper motor controller is used to connect the quantum dot optical amplifier and the wavelength tunable filter together to finally complete the device integration. Tunable laser wavelength tunable range of 44nm, is the maximum tuning value is known, not only as a light source integrated with other optical components of silicon optical platform can also be used as a single-chip broadband communications transceiver Module, but also for biomedical imaging, such as optical coherence tomography. Part of this research was funded by the Strategic Information and Communications Research and Development Promotion Program, a project financed by the Ministry of Interior and Communications and Japan's Social Science Research Grant to promote scientific research. High speed door servo system motor and controller servo system motor and controller,PVC soft-curtain high speed door motor,servo motor,rapid roller doors, PVC high speed auto recovery rolling door SHENZHEN HONGFA AUTOMATIC DOOR CO., LTD , http://www.hongfarrs.com