Dispersive CombSpectrum Interferometer Metrological Characterization Wiroj Sudatham 48430402

Dispersive Comb-Spectrum Interferometer: Metrological Characterization Wiroj Sudatham 48430402 Industrial Metrology Program KMUTT 17/01/2006 Umberto Minoni, Luigi Rovati, M. Bonardi, and Franco Docchio (Owner) IEEE TRANSACTION ON INSTRUMENTATION AND MEASUREMENT, VOL. 48, NO. 6, DECEMBER 1999

Objective & Scope q Introduction to DSCI Modeling tools for nonincremental q Principle of measurement distance measurement q Analytical of uncertainty sources Low-cost implementation, using a q Experimental Results commercial low-cost laser diode q Analytical uncertainty sources q Application for the development industrial sensors 6/5/2021 Seminar – S. Wiroj 2 DSCI - Introduction

Introduction Interferometer q Tools, widely used in nonincremental distance measurement q Many type (difference component) q Interference of light waves q Principle of superposition q Coherence light source q Light Sources (normally used laser) 6/5/2021 Seminar – S. Wiroj 3 DSCI - Introduction

Introduction Dispersive Comb Spectrum Interferometer - DCSI q Michelson’s Interferometer System q White Light (LD 670 nm) q Diffraction Grating q Littrow Configuration 6/5/2021 Seminar – S. Wiroj 4 DSCI - Introduction

Introduction Why DCSI ? q Easy to optical setup and mechanical moving parts q Robust and reliable configurations q high-accuracy q Using a commercial low cost laser diode as the light source 6/5/2021 Seminar – S. Wiroj 5 DSCI - Introduction

Principle Of Measurement Setup RM MM LD MM BS 1 CC TC BS 2 CCD L 1 L 2 Littrow Configuration DG 6/5/2021 Seminar – S. Wiroj 6 DSCI – Principle Of Measurement

Principle Of Measurement § The CCD Camera for the spectral component detection and transfer to computer § Littrow configuration exhibits adequate spectral resolution to study interference phenomena of each lasing modes 6/5/2021 Seminar – S. Wiroj 7 DSCI – Principle Of Measurement

Principle Of Measurement § Signal processing The interference signal before sampling Simulated signal at the output of the camera § The sampling distance to frequency be measured is given S can by the be spectral frequency evaluated by gauging of thelasing period modes Tcos 6/5/2021 Seminar – S. Wiroj 8 DSCI – Principle Of Measurement

Uncertainty Sources Two main cases q Light source and its controls § Line width of each lasing modes § The value of center frequency q Optical setup including the detection of the interference signal § Drift from the diffraction grating § Drift from the CCD detection 6/5/2021 Seminar – S. Wiroj 9 DSCI – Uncertainty Sources

Uncertainty Sources Uncertainty Model not be easily calculated Where, Assuming a negligible change of air refractive indexmapping optical freq onto the time scale of the camera signal 6/5/2021 Seminar – S. Wiroj 10 DSCI – Uncertainty Sources

Experiment Results Laser Characterization q The best condition § Operating at 43 m. A § Temperature in the range from 8 o. C to 14 o. C 6/5/2021 Seminar – S. Wiroj 11 DSCI – Experiment Results

Experiment Results Laser Characterization q Fringes visibility § if not, no aliasing phenomena are present should be § The range of measurement § Experiment result 6/5/2021 Seminar – S. Wiroj 12 DSCI – Experiment Results

Experimental Results Numerical Case = = §Components A numerical estimate of Data be. Uncertainty used the measurement uncertainty § Used data from prototype implementation and § Laser source The combined uncertainty of the measuring characterization range 800 mm corresponding to about 1. 4 mm 6/5/2021 Seminar – S. Wiroj 13 DSCI – Experiment Results

Experiment Results Distance Measurements § Operating at 8 o. C § 42 m. A § Environment 22 o. C § SD of error is 1. 3 mm q Calibration a implementation of the system with interferometer traced to international standard q The sensitivity to l 0 , that the laser has a temperature coefficient of 0. 39 nm/o. C 6/5/2021 Seminar – S. Wiroj 14 DSCI – Experiment Results

Conclusion q Supportable both theory and experimental results q Suitable to carry out measurement over up to about 1 mm q Uncertainty of 0. 18% q Low-cost commercial source q Application for the development of industrial sensors. 6/5/2021 Seminar – S. Wiroj 15 DSCI – Conclusion

THE END. Presentation by S. Wiroj Dispersive Come-Spectrum Interferometer: Metrological Characterization AND THANK YOU FOR ATTENTION. Umberto Minoni, Luigi Rovati, M. Bonardi, and Franco Docchio (Owner) 6/5/2021 16 IEEE TRANSACTION ON INSTRUMENTATION AND MEASUREMENT, VOL. 48, NO. 6, DECEMBER 1999