Persistent Link:
http://hdl.handle.net/10150/288920
Title:
Solid-state Raman image amplification
Author:
Calmes, Lonnie Kirkland
Issue Date:
1998
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
Amplification of low-light-level optical images is important for extending the range of lidar systems that image and detect objects in the atmosphere and underwater. The use of range-gating to produce images of particular range bins is also important in minimizing the image degradation due to light that is scattered backward from aerosols, smoke, or water along the imaging path. For practical lidar systems that must be operated within sight of unprotected observers, eye safety is of the utmost importance. This dissertation describes a new type of eye-safe, range-gated lidar sensing element based on Solid-state Raman Image Amplification (SSRIA) in a solid-state optical crystal. SSRIA can amplify low-level images in the eye-safe infrared at 1.556 μm with gains up to 106 with the addition of only quantum-limited noise. The high gains from SSRIA can compensate for low quantum efficiency detectors and can reduce the need for detector cooling. The range-gate of SSRIA is controlled by the pulsewidth of the pump laser and can be as short as 30-100 cm, using pump pulses of 2-6.7 nsec FWHM. A rate equation theoretical model is derived to help in the design of short pulsed Raman lasers. A theoretical model for the quantum noise properties of SSRIA is presented. SSRIA results in higher SNR images throughout a broad range of incident light levels, in contrast to the increasing noise factor with reduced gain in image intensified CCD's. A theoretical framework for the optical resolution of SSRIA is presented and it is shown that SSRIA can produce higher resolution than ICCD's. SSRIA is also superior in rejecting unwanted sunlight background, further increasing image SNR. Lastly, SSRIA can be combined with optical pre-filtering to perform optical image processing functions such as high-pass filtering and automatic target detection/recognition. The application of this technology to underwater imaging, called Marine Raman Image Amplification (MARIA) is also discussed. MARIA operates at a wavelength of 563 nm, which passes most efficiently through coastal ocean waters. The imaging resolution of MARIA in the marine environment can be superior to images produced by laser line scan or standard range-gated imaging systems.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Engineering, Marine and Ocean.; Physics, Optics.; Engineering, Materials Science.; Remote Sensing.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Optical Sciences
Degree Grantor:
University of Arizona
Advisor:
Powell, Richard C.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleSolid-state Raman image amplificationen_US
dc.creatorCalmes, Lonnie Kirklanden_US
dc.contributor.authorCalmes, Lonnie Kirklanden_US
dc.date.issued1998en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractAmplification of low-light-level optical images is important for extending the range of lidar systems that image and detect objects in the atmosphere and underwater. The use of range-gating to produce images of particular range bins is also important in minimizing the image degradation due to light that is scattered backward from aerosols, smoke, or water along the imaging path. For practical lidar systems that must be operated within sight of unprotected observers, eye safety is of the utmost importance. This dissertation describes a new type of eye-safe, range-gated lidar sensing element based on Solid-state Raman Image Amplification (SSRIA) in a solid-state optical crystal. SSRIA can amplify low-level images in the eye-safe infrared at 1.556 μm with gains up to 106 with the addition of only quantum-limited noise. The high gains from SSRIA can compensate for low quantum efficiency detectors and can reduce the need for detector cooling. The range-gate of SSRIA is controlled by the pulsewidth of the pump laser and can be as short as 30-100 cm, using pump pulses of 2-6.7 nsec FWHM. A rate equation theoretical model is derived to help in the design of short pulsed Raman lasers. A theoretical model for the quantum noise properties of SSRIA is presented. SSRIA results in higher SNR images throughout a broad range of incident light levels, in contrast to the increasing noise factor with reduced gain in image intensified CCD's. A theoretical framework for the optical resolution of SSRIA is presented and it is shown that SSRIA can produce higher resolution than ICCD's. SSRIA is also superior in rejecting unwanted sunlight background, further increasing image SNR. Lastly, SSRIA can be combined with optical pre-filtering to perform optical image processing functions such as high-pass filtering and automatic target detection/recognition. The application of this technology to underwater imaging, called Marine Raman Image Amplification (MARIA) is also discussed. MARIA operates at a wavelength of 563 nm, which passes most efficiently through coastal ocean waters. The imaging resolution of MARIA in the marine environment can be superior to images produced by laser line scan or standard range-gated imaging systems.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectEngineering, Marine and Ocean.en_US
dc.subjectPhysics, Optics.en_US
dc.subjectEngineering, Materials Science.en_US
dc.subjectRemote Sensing.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineOptical Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorPowell, Richard C.en_US
dc.identifier.proquest9912130en_US
dc.identifier.bibrecord.b39124137en_US
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