Spectrometer-on-a-chip shows young universe

Compiled by Photonics Spectra staff

NASA scientists hoping to get a glimpse of the universe in its youth may finally do so using a revolutionary instrument on a chip called MicroSpec.

Scientists know what the universe looked like when it was a baby and how it looks today, but they don’t know how it looked in adolescence. The new instrument-on-a-chip developed at NASA’s Goddard Space Flight Center is expected to provide a picture of how the cosmos developed into the kind of place that could support life such as that found on Earth.

The MicroSpec is a spectrometer that is 10,000 times more sensitive and much smaller than current state-of-the-art devices. The small platform, with all of its components fitting onto a silicon wafer that measures 4 in. in diameter, is designed to gather data of objects so distant from Earth that they no longer can be observed in visible light, only in the infrared bands of the electromagnetic spectrum. The scientists hope that it will measure the object’s composition and other physical properties.

MicroSpec, pictured here on a 4-in. silicon wafer, could provide a picture of how the cosmos developed into the kind of place that could support life such as that found on Earth. Courtesy of NASA.

Now under development, the instrument is a contender for future flight missions in astrophysics and earth science, said Harvey Moseley, an astrophysicist and leader of the development effort. It is ideally suited for studying the evolution of the universe.

Past NASA missions studied the infant universe, gathering information about the primordial light generated during the universe’s creation. The missions detected tiny temperature differences, which pointed to density differences that gave rise to the first stars and galaxies formed 400 trillion years after the Big Bang. However, scientists have not yet studied these objects with precision, nor have they studied the light emitted by the life-sustaining elements created in the first stars and later distributed across the universe in stellar explosions.

“The formation of stars and the nuclear reaction that took place inside these first stars have created essentially all the elements that constitute the things that we see around here – the carbon in our bodies and the iron and hemoglobin in our blood,” Moseley said.

By building the MicroSpec, scientists will be able to see how the universe developed into a place that can support life such as ours. Its components –including detectors, optics and filters – would be assembled on a silicon wafer measuring about 400 μm thick and 4 in. in diameter, so it can be mass-produced. NASA could produce multiple devices and assemble them as one compact instrument. Contributing to its increased sensitivity, the scientists hope to use an advanced Goddard-developed cooling system that would chill the MicroSpec to just a tenth of a degree above absolute zero.

With its sensitivity and small size, the researchers say it could be suitable for all types of missions, including large observatories such as the Hubble Space Telescope and suborbital missions carried out on balloons and aircraft.