研究成果藝廊

開啟圖片

Internal photos of Laser Synthesizer instrument: left - top view of optical circuitry including Erbium Doped Fiber Amplifier and custom Fiber Bragg Grating filter assembly; right - bottom view of RF power amplifier, Mach-Zehnder modulator, DC power supplies (x3), and monitor & control. Developed at the SMA project office by Derek Kubo and Ranjani Srinivasan in collaboration with NAOJ, this instrument was designed to provide a pure optical local oscillator reference for distribution over long distances of optical fiber (Kubo et al. Aug 2013, IEEE T Microw Theory: 61(8), 3005-3014).

This Laser Synthesizer is based on the use of a Mach-Zehnder modulator and was developed for the ALMA project as a demonstration of an alternative approach. The packaging design utilizes a custom optics plate housed within a 19 x 22 x 8.75 inch rack mountable EMI chassis. Operation at 5000 meters is facilitated with forced air cooling and thermal sensors for remote temperature monitoring. A companion Local Oscillator Reference Test Module instrument based on a similar architecture was developed after the completion of the Laser Synthesizer and was deployed at the East-Asia Front End Integration Center to support the ALMA front end receiver production line.