Georgia Institute of Technology engineers have designed a new microspectrometer with high resolution and wide bandwidth.
Microspectrometer micrograph
Integrated lab-on-chip sensing systems require large off-chip spectrometers for achieving a high resolution. Conventional spectrometers are bulky and expensive. Efforts to reduce cost and size have led to a lower resolution. Georgia Tech engineers used 2 ì radius microdonut resonators and designed an 81-channel on-chip spectrometer that achieved 0.6 nm resolution with a less than 1 sq.mm footprint over a 50 nm spectral range.
The microspectrometer was designed using fabrication processes with CMOS compatibility. The miniaturized microdonut resonator array is the key element in the device. The researchers engineered the geometry and made adjustments to the resonance wavelengths of the microdonut resonators. They performed fine-tuning through adjustment of the inner radius of the resonators, as the outer radius was highly sensitive to variations. Each microdonut resonator was designed to tap only a small portion of the inbound spectrum, enabling real time measurement of the complete spectrum of preferred wavelengths. The operating bandwidth and resolution could be independently configured and controlled.
The advantages of the instrument would allow it to be integrated with devices including microfluidic channels, optoelectronics, microelectronics, and sensors and can be used in pharmaceutical, medical, chemical and biological applications.