Educational

Tutorial Videos

This section provides material to aid students in getting started on various experimental techniques commonly found in optics laboratories.

1)How to conveniently and efficiently couple a laser beam into a single mode optical fiber

With a core diameter of just a few micrometers, single mode fibers are considerably more difficult to couple than multimode fibers. This video introduces students to a procedure that is simple and achieves high coupling efficiency in a short period of time using just two mirrors and a fiber collimator. Video produced by B. Petrak, M. Peiris and K. Konthasinghe.

2) How to align an external cavity diode laser (ECDL) in Littrow configuration

ECDLs are simple, low-cost and high-quality sources of frequency-tunable laser light. Alignment of an ECDL in Littrow configuration is illustrated on a table-top setup. Video produced by B. Petrak, M. Peiris, K. Konthasinghe, and D. Lage.

National Science Foundation support: DMR No. 1254324

Defense Threat Reduction Agency support: HDTRA No. 12-1-0040

3) How to rapidly set up and align a Michelson interferometer using retroreflectors

A simple procedure is described to set up a Michelson interferometer for use as a tool for the measurement of optical pulse width/coherence time. Video produced by B. Petrak, M. Peiris, and K. Konthasinghe.

3) How to rapidly set up and align a Michelson interferometer using retroreflectors

A simple procedure is described to set up a Michelson interferometer for use as a tool for the measurement of optical pulse width/coherence time. Video produced by B. Petrak, M. Peiris, and K. Konthasinghe.

4) How to set up and align a scanning Fabry-Perot interferometer

The scanning Fabry-Perot interferometer is a valuable laboratory tool for the measurement of spectra with a resolution that can be much higher than that of other spectroscopic instruments such as grating spectrometers. This video describes a simple construction of a non-confocal scanning Fabry-Perot interferometer and the mode-matching of an external input beam (here a single mode fiber) to the TEM00 modes of the Fabry-Perot resonator. Video produced by B. Petrak, M. Peiris, and K. Konthasinghe.

5) How to set up and align an optical Faraday Isolator

In high-resolution spectroscopy the Faraday isolator is an essential tool used for minimizing unwanted back-reflections that tend to perturb the operation of lasers. This video explains how to quickly setup a Faraday isolator in free space. Video produced by B. Petrak, M. Peiris, and K. Konthasinghe.

6) How to set up and align a long-range scanning Michelson interferometer with high fringe visibility

In video 3) the setup of a Michelson interferometer was described. In the present tutorial video, it is shown how such an interferometer can be constructed for the case where a long scanning range is needed. Video produced by Y. Nieves and M. Peiris.

National Science Foundation support: ECCS No. 2116275

7) How to set up and align a multipass cavity

When it is desirable to enhance light matter interactions without involving a resonance condition, multipass cavities can be employed. This video describes the alignment of a multipass cavity built from two concave mirrors. Here the light source is a Helium Neon laser. However, spatially multimode and spectrally impure light can be introduced as well. Video produced by J. Singh.

8) Identifying common household chemicals with feedback-assisted multipass Raman scattering

This video illustrates the high sensitivity, versatility, and responsiveness of feedback-assisted multipass spontaneous Raman scattering. Daily use items such as windex, markers, whipped cream generate gases with unique signatures that can be unambiguously identified and quantified at trace levels (parts-per-million and below). Video produced by J. Singh.