[Lab on a chip] A dynamic strategy for wavelength sensing using the diffracted orders of a grating
We propose a strategy for real time multicolour detection of light emitting particles under flow conditions, using the diffracted orders of a grating. The method relies on the fact that the spatial (angular/linear) separation between the orders of a diffraction grating is a wavelength dependent quantity. Thus, the difference in arrival times at a fixed detector for neighbouring orders produced by a moving, light-emitting particle can be used as a wavelength sensing mechanism. We demonstrate this functionality using a prototype PDMS microfluidic device that incorporates a focusing transmission grating. A key attribute of this approach is that it requires only a single sensitive detector, such as a photomultiplier tube, in contrast to many conventional approaches which require multiple sensitive detectors or a detector array.
Seyed M. Azmayesh-Fard,a Aaron Melnyk,a Lawrence Lam,b Trevor Allen,a Robert Fedosejevsa and Ray G. DeCorby*a
* Corresponding authors
a Department of Electrical and Computer Engineering, University of Alberta, ECERF Building, 9107 - 116 Street, N.W., Edmonton, Canada E-mail: firstname.lastname@example.org Tel: +1 780 492 5585
b Innovation Center, National Institute for Nanotechnology (NINT), 11421 Saskatchewan Drive, Edmonton, Canada