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Cavity-Enhanced On-Chip Absorption Spectroscopy

Detailed Technology Description

Cornell's new laser absorption spectrometry device-on-a-chip demonstrates sensitivity equal to that of typical macroscopic spectroscope in a device with a footprint of 0.03 mm2.

Others

• Issued US patent 8,992,836

• Arthur Nitkowski, Long Chen, and Michal Lipson, "Cavity-enhanced on-chip absorption spectroscopy using microring resonators," Optics Express 16, 11930-11936 (2008)

*Abstract

Cornell's new laser absorption spectrometry device-on-a-chip demonstrates sensitivity equal to that of typical macroscopic spectroscope in a device with a footprint of 0.03 mm². The miniature laser absorption spectrophotometer achieves significantly enhanced interaction between light and samples as small as 200 nanoliters by using microring resonators with integrated waveguides and silicon-based microfluidic channels. This novel design avoids the shortened optical path for absorption and reduced ability to detect absorbing species that typically is the result of the miniaturization of laser absorption spectroscopy devices.

 

Because at resonance, light circulates many times within the ring resonator, the actual interaction length between the light and liquid is greater by several orders of magnitude than the circumference of the ring resonator itself (up to 5 mm). By extracting the absorption contribution of a species to one resonance and repeating the process for many resonances over a range of wavelengths, an absorption spectrum can be determined. In one experiment, the absorption spectra of less than 200 nL of N-methylaniline was measured with 1 nm resolution from 1460 nm to 1610 nm. The wavelength range of the device is only limited by laser tunability and in principle measurements can be extended from 1.2 to 6 μm using silicon waveguides.

 

Cornell's spectroscopy device boasts a micrometer-scale size that allows multiple parallel measurements and integration with other measurement techniques on a single chip. With an appropriate light source and choice of fabrication materials, the device could be operated throughout the visible and infrared wavelengths. This technique can help realize a completely on-chip spectroscopy device for label-free massively parallel detection of analytes for lab-on-a-chip applications.

 
Potential Applications
• On-chip spectroscopy device
• Handheld or portable spectroscope
• Label-free, massively parallel detection of analytes for lab-on-a-chip applications.

Advantages
• Micrometer-scale size
• Parallel measurements on a single chip
• Can be integrated with other chip-based detection and analysis techniques
• Sensitivity equivalent to commercially available desktop spectrometers
• Waveguide integrated and broadband absorption spectroscopy

*Licensing

Patrick Govangpjg26@cornell.edu(607) 254-2330

Country/Region

USA