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|Title:||Application of electroabsorption in a semiconductor laser for electromagnetic field sensing|
|Author(s):||Genis, Patrick Charles|
|Doctoral Committee Chair(s):||Verdeyen, Joseph T.|
|Department / Program:||Electrical and Computer Engineering|
|Discipline:||Electrical and Computer Engineering|
|Degree Granting Institution:||University of Illinois at Urbana-Champaign|
|Subject(s):||Engineering, Electronics and Electrical
Physics, Condensed Matter
|Abstract:||The application of electroabsorption in an AlGaAs quantum-well semiconductor laser device for optically based electromagnetic field sensing has been studied. A separate confinement heterostructure laser design containing a single quantum well and a steplike waveguiding index profile has demonstrated efficient modulation when operated as a light absorber rather than as an emitter.
Observations of changes in the transmitted optical power through this device as a function of the applied forward and/or reverse dc bias have demonstrated nearly linear transfer functions for a given operating wavelength. Measurable changes in transmission were also observed for relatively small changes in applied voltage ($\approx$100 $\mu$V) allowing for the possibility of sensors with high sensitivity. Investigation of the high frequency operation of the device has shown a one-to-one correspondence in amplitude and phase between the applied RF voltage and the modulation of the transmitted optical power over a wide frequency range ($>$1 GHz). Linear operation has been observed for a dynamic range exceeding 75 dB of the applied RF power at 20 MHz.
Experiments that had coupled receiving antennas to a modulator have demonstrated the ability to measure an incident electric field of 34 V/m with a 300 MHz bandwidth and the corresponding time derivative of the magnetic field with a 30 MHz bandwidth. At 20 MHz, electric fields as small as 2 V/m have been measured. A 24 dB dynamic range in the measured electric field has been demonstrated and an expected range of 75 dB would imply the ability to measure fields larger than 10$\sp4$ V/m.
The demonstrated performance characteristics of wide bandwidth operation and linear response with respect to the applied voltage make these types of semiconductor structures attractive for wide-band electromagnetic field sensing as well as for other low-power modulation applications.
|Rights Information:||Copyright 1990 Genis, Patrick Charles|
|Date Available in IDEALS:||2011-05-07|
|Identifier in Online Catalog:||AAI9114244|
This item appears in the following Collection(s)
Dissertations and Theses - Electrical and Computer Engineering
Dissertations and Theses in Electrical and Computer Engineering
Graduate Dissertations and Theses at Illinois
Graduate Theses and Dissertations at Illinois