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Southern Polytechnic State University ECET 3410 Laboratory Exercise No. 10
Electrical and Computer Engineering Technology Optical Spectrum Analysis
Introduction
In this exercise you will work with some of the information discussed in class and in your textbook to become
acquainted with spectral measurements and the MS96A Optical Spectrum Analyzer.
Cautions
Never connect an LED to a DC supply without an appropriate series current-limiting resistor. Always check the
polarity of the supply before energizing – reverse biasing the LED will destroy it immediately.
Procedure
Note: this TYPEFACE literally denotes a control on an instrument’s front panel
this TYPEFACE literally denotes a label on an instrument’s front panel
1. Characterize the wavelength-color perception of your primitive optical test set (that is, your vision system) by
finding what colors correspond to what wavelength ranges for your vision. Use the Fiberoptic Illuminator
Model 77503 and set the INTENSITY control such that the lamp-drive in ≤ 10.0 V. Test your vision
between 400nm ≤ λ ≤ 700nm by projecting the output beam on a white surface and recording at which
wavelengths you perceive the spectral colors to change.
2. Set the Fiberoptic Illuminator to output red light. Introduce the output beam into the input port of the
MS96A Optical Spectrum Analyzer. Display and make a hardcopy record of the spectrum of this red light
(PRINT).
The best way to find the spectrum is to select LOG (Scale), AUTOSCALE, and SINGLE (Sweep Mode).
Then, refine the display using the WAVELENGTH and SCALE controls until the spectrum display is
adequate. Finally, choose LINEAR (Scale) so that your spectrum will be comparable to those on data-
sheets and in your textbook. Print a hardcopy of this final spectrum display using the instrument’s internal
printer.
3. Repeat the procedure of step 2 to display the linear spectrum of a 12-V incandescent lamp. Print a copy of
the displayed spectrum.
4. Repeat the procedure of step 2 to display the linear spectrum of a T-1510 (or similar) fiberoptic LED biased
at a forward current of ≤ 40mA. Print a copy of the displayed spectrum.
5. If available, repeat the procedure of step 2 to display the linear spectrum of a He-Ne (red) laser. Print a
copy of the displayed spectrum
