Beam Scanning Confocal Differential Heterodyne Interferometry

Cheol Song, Tae Joong Kim, Dae-Gab Gweon
2007 International Journal of Optomechatronics  
This paper presents a new approach to the design of confocal differential heterodyne interferometer (CDHI) which is a combination of differential heterodyne interferometer (DHI) with confocal laser scanning microscopy (CLSM). The CDHI can measure a step height over a quarter of wavelength of the light source, which can not be accurately measured by DHI and CLSM respectively. The approach is that it utilizes a beam scanning method instead of transporting a sample to be measured. The measurement
more » ... esults carried out for samples having step height are found to be comparable in precision with those of the measured by commercial scanning electron microscopes.
doi:10.1080/15599610701261076 fatcat:vswuonex3fhfzdajccpfmxb23e