Note: A simple multi-channel optical system for modulation spectroscopies
| Autor: | Kai-Wei Chen, R. Castro-García, G. Flores-Rangel, J. Solís-Macías, L. F. Lastras-Martínez, R. E. Balderas-Navarro, Jian-Jhih Ciou, J. D. Sánchez-López, J. M. Flores-Camacho, Chang-Hsiao Chen |
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| Rok vydání: | 2018 |
| Předmět: |
Materials science
Photoelastic modulator Spectrometer business.industry Amplifier System of measurement 02 engineering and technology 021001 nanoscience & nanotechnology 01 natural sciences Spectral line 010309 optics Optics Modulation 0103 physical sciences Slow response 0210 nano-technology business Instrumentation Multi channel |
| Zdroj: | The Review of scientific instruments. 88(12) |
| ISSN: | 1089-7623 |
| Popis: | 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. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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