abstract

• Photoreflectance-difference (PR/PRD) and reflectance-difference (RD) spectroscopies employ synchronic detection usually with lock-in amplifiers operating at moderate (200-1000 Hz) and high (50-100 KHz) modulation frequencies, respectively. Here, we report a measurement system for these spectroscopies based on a multichannel CCD spectrometer without a lock-in amplifier. In the proposed scheme, a typical PRD or RD spectrum consists of numerical subtractions between a thousand CCD captures recorded, while a photoelastic modulator is either operating or inhibited. This is advantageous and fits the slow response of CCD detectors to high modulation frequencies. The resulting spectra are processed with Savitzky-Golay filtering and compared well with those measured with conventional scanning systems based on lock-in amplifiers. © 2017 Author(s).

authors

• Balderas Navarro Raúl Eduardo
• Castro García Ricardo
• Chen C.-H.
• Chen K.-W.
• Ciou J.-J.
• Flores Camacho José Manuel
• Flores-Rangel G.
• Lastras Martínez Luis Felipe
• Solís-Macías J.
• Sánchez-López J.D.

publication date

• 2017-01-01

funding provided via

• 252867  Grant
• 483-DSA/103.5/14/10476  Grant
• Ministry of Science and Technology, MOST: 104-2628-E-035-002-MY3, 106-2221-E-035-088-MY3  Grant

published in

• Review of Scientific Instruments  Journal

keywords

• Locks (fasteners); Modulation; Molecular spectroscopy; Optical signal processing; Optical systems; High modulation frequency; Measurement system; Modulation frequencies; Modulation spectroscopy; Multi-channel optical system; Photo-elastic modulator; Reflectance differences; Savitzky Golay Filtering; Frequency modulation

Digital Object Identifier (DOI)

• 10.1063/1.4998596

PubMed ID

• 29289180

start page

end page

volume

• 88

issue

• 12