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Title: Doppler optical coherence microscopy and tomography applied to inner ear mechanics

While it is clear that cochlear traveling waves underlie the extraordinary sensitivity, frequency selectivity, and dynamic range of mammalian hearing, the underlying micromechanical mechanisms remain unresolved. Recent advances in low coherence measurement techniques show promise over traditional laser Doppler vibrometry and video microscopy, which are limited by low reflectivities of cochlear structures and restricted optical access. Doppler optical coherence tomography (DOCT) and Doppler optical coherence microscopy (DOCM) both utilize a broadband source to limit constructive interference of scattered light to a small axial depth called a coherence gate. The coherence gate can be swept axially to image and measure sub-nanometer motions of cochlear structures throughout the cochlear partition. The coherence gate of DOCT is generally narrower than the confocal gate of the focusing optics, enabling increased axial resolution (typically 15 μm) within optical sections of the cochlear partition. DOCM, frequently implemented in the time domain, centers the coherence gate on the focal plane, achieving enhanced lateral and axial resolution when the confocal gate is narrower than the coherence gate. We compare these two complementary systems and demonstrate their utility in studying cellular and micromechanical mechanisms involved in mammalian hearing.
Authors:
;  [1] ;  [2] ;  [1]
  1. Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States)
  2. (United States)
Publication Date:
OSTI Identifier:
22494503
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 1703; Journal Issue: 1; Conference: 12. international workshop on the mechanics of hearing, Cape Sounio (Greece), 23-29 Jun 2014; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AUDITORY ORGANS; DEPTH; FOCUSING; IMAGES; INTERFERENCE; LASERS; MECHANICS; MICROSCOPY; OPTICS; TOMOGRAPHY; TRAVELLING WAVES