Optics DIY - Smartphone-based Self-Referencing Spectrometer by Chuong Tran

Objective

To provide Open Source Software, Hardware Designs, and Tutorials for learning how to design and build a  Smartphone-based Self-Referencing Spectrometer.  Spectrometer is used to shows the unique light patterns of the sample materials which serve as identifying markers for evaluating unknown materials. 

Why use a self-referencing spectrometer?

Wavelength accuracy of typical spectrometers must be calibrated in advance to establish the relation between the pixel number and the associated wavelength by means of a calibration lamp with known emission line wavelengths. In addition, a recalibration has to be performed periodically since the pixel number versus wavelength relation can change with variations of the auto-focusing lens position commonly occurs in smartphones.  Given that this calibration procedure has to be performed off-line, it would be desirable to address the need for a smartphone-based optical spectrometer that has simultaneous self-referencing and spectrum measurement capabilities to achieve excellent wavelength reproducibility. 

Aim of Project EigenCAM

It is therefore an aim of Project EigenCAM to provide a novel spectrometer system that can simultaneously self-referencing and measuring spectral characteristics in real time with the use of software App.  The concurrent measure and self-calibrate capabilities makes it possible as an attachment spectrometer on a mobile computing device without requiring an off-line calibration.