Direct and quantitative broadband absorptance micro/nano spectroscopy using FTIR and bilayer cantilever probes

Optical properties of micro/nano materials are important for many applications in biology, optoelectronics, and energy. In this thesis, a method is described to directly measure the quantitative absorptance spectra of micro/nano-sized structures using Fourier Transform Spectroscopy (FTS). The measurement technique combines optomechanical cantilever probes with a modulated broadband light source from an interferometer for spectroscopic measurements of objects. Previous studies have demonstrated the use of bilayer (or multi-layer) cantilevers as highly sensitive heat flux probes with the capability of resolving power as small as ~4 pW. Fourier Transform Spectroscopy is a well-established method to measure broadband spectra with significant advantages over conventional dispersive spectrometers such as a higher power throughput and large signal-to-noise ratio for a given measurement time. By integrating a bilayer cantilever probe with a Michelson interferometer, the new platform is capable of measuring broadband absorptance spectra from 3prm to 18pm directly and quantitatively with an enhanced sensitivity that enables the characterization of micro- and nanometer-sized samples, which cannot be achieved by using conventional spectroscopic techniques. Besides, a paralleled project of a bi-armed cantilever decouples the sample arm and the probe arm to further enhance the signal-to-noise ratio.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Mechanical Engineering.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2012

Author dc:creator

• Hsu, Wei-Chun

Advisor dc:contributor.advisor

• Gang Chen.

• Mechanical Engineering.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/78182

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/78182