Ren

Spring Semester 2008 Teaching

Research

Solar Adaptive Optics: We are developing a Universal Adaptive Optics (AO) for solar telescope. Compared with other solar AO systems, our system will be able to deliver extremely high Strehl Ratio (i.e. extremely high correction). The well-corrected solar images will be critical for high-sensitivity solar magnetic field investigation, since scattered light induced by the atmosphere turbulence is dramatically reduced; We are also developing solar Multi-Conjugate AO (MCAO) system, which uses several deformable mirrors to correct the atmosphere turbulence in different altitudes so that a large and uniform corrected field of view is available. Because of the complex of the MCAO system, currently no any MCAO system is available on an astronomical site.

Seeing Testing: We have built a wave-front sensor called Differential Image Motion Monitor (DIMM) for solar seeing test of an astronomical site. The DIMM has a number of advantages over other approaches. Although the DIMM technique is widely used for stellar night-time testing where the target for wave-front sensing is a pint source, it is rarely used for solar seeing test where the target is a 2-dimensional structure and therefore cross-correlation technique is needed to track the solar structure. A movie of recent test at SFO using our recently developed wave-front sensor is available. The testing was performed at Feb. 27, 2008 by using sunspot 983, which indicates that excellent seeing conditions (r0 up to 100 mm) is available at the SFO!

3-D Image Spectroscopy: Supported by the National Science Foundation under the grant AST 05-01743, we are developing the 3-dimentional (3-D) image spectroscopy technique. Compared with other conversional spectrometer, the 3-D image spectroscopy technique allows the 3-D data tube (x, y spatial and spectrum information) to be collected in a single exposure. This is critical for the astronomical spectroscopy over a 2-dimentional field of view, such as the Sun.

Direct Detection of Earth-Like Planets: In collaboration with Nanjing Institute of Astronomical Optics and Technology, Chinese Academy of Sciences, China, we are developing high-contrast imaging techniques that will allow us eventually directly imaging of Earth-like planets that have life at an extra-solar system. This will answer the most fundamental scientific questions such as "are we alone in the universe?". The direct imaging of Earth-like planets will be one of the most important scientific advances in the next decade. We invented a technique called Stepped-Transmission Filter based coronagraph. Currently a prototype is being developed and progresses are being made.

Research Group

Deqing Ren (Assistant professor)
Mr. Vincent Tagliamonti (Graduate Student)
Mr. Dou Jingpei (Graduate Student, In collaboration with Nanjing Institute of Astronomical Optics and Technology, China)
Mr. Xi Zhang (Graduate Student, In collaboration with Nanjing Institute of Astronomical Optics and Technology, China)

News: accept graduate students and visiting scholars !