Photonics Spectra BioPhotonics Vision Spectra Photonics Showcase Photonics Buyers' Guide Photonics Handbook Photonics Dictionary Newsletters Bookstore
Latest News Latest Products Features All Things Photonics Podcast
Marketplace Supplier Search Product Search Career Center
Webinars Photonics Media Virtual Events Industry Events Calendar
White Papers Videos Contribute an Article Suggest a Webinar Submit a Press Release Subscribe Advertise Become a Member


Acousto-Optic Devices


ACOUSTO-OPTIC SCANNING DEVICES: CHARACTERISTICS

MODULATORS

              
 Material      
Bandwidth     
   (MHz)		   Rise Time     
    (ns)		        Acousto
Input Power (W)     
   (Saturation)		      Material
Wavelength
Range (µm)		      
       Efficiency at
Maximum Bandwidth
          (633 nm)
                       
  Glass     5 - 10     50         1 - 6     0.4 - 25        >70%
  PbMoO4     >80     4 - 6         0.5 - 1.5     0.42 - 5.5        >70%
  TeO2     >80     4 - 6         0.5 - 1.5  
  0.35 - 5        >70%
  Germanium
    10     70         20 - 30
     2 - 20
         >50% at 10.6 µm
   GaP     100 - 1500

  10 - 0.7
         0.5 - 2     0.6 - 1
       >80%
  GaAs     50 - 200
  20 - 5
        0.5 - 2

  1 - 1.6        >30% at 1.5 µm

DEFLECTORS

                       
 Type              
  Resolution           
  Scan Speed            
 (Spots/µs)		   Acoustic Power
         (W)		             
Wavelength Range
            (µm)
                   
  PbMoO4     >1500        15        <5          0.42 - 5.5
  TeO2     >2000        20        <5          0.35 - 5
  Glass     <1000        10        <5          0.4 - 2.5
  Germanium     600 - 800        5        100 - 150          2 - 20
  TeO2 chirp     ~2000        >20        <1 (avg.)          0.35 - 5
  Gap     ~2000        1000        <1          0.6 - 1
  GaAs     ~400        200        <1          1 - 1.6

ACOUSTO-OPTIC FIGURES OF MERIT

                       Material                Acoustic Mode            
  Figure of Merit (M2)
        (S3/kg)		              
Acoustic Velocity
       (mm/µs)
               
  Flint glass (SF 4)                  Longitudinal         4.51 x 10—15             3.63
  TeO2                  Longitudinal         34.5 x 10—15             4.2
  TeO2                  Shear          793 x 10—15             0.617
  PbMoO4                  Longitudinal         36.3 x 10—15             3.63
  GaP                  Long            30 x 10—15             6.32
  GaP                  Shear            16 x 10—15             4.13
  GaAs                  Long          104 x 10—15             5.15
  GaAs                  Shear            46 x 10—15             3.32


ACOUSTO-OPTIC PROCESSOR DEVICES:
PROBLEMS AND SOLUTIONS

         Problem  
  Cause                                                            
  Solution
  Limited bandwidth   Transducer impedance
mismatch		   Acoustic impedance matching (quarter-wave layers)
           
  Quadratic phase error       Quarter-wave matching, frequency plane phase filter
           
  Limited bandwidth   Acousto-optic interaction   Birefringent diffraction
Beam steering
           
  Frequency distortion/ frequency blurring   Acoustic dispersion   Increasing interaction length
(limited bandwidth)
Optical beam apodization
Increasing transducer height
Acoustic Beam apodization
Birefringent diffraction
Material selection
           
  Limited resolution
slide lobes		   Optical diffraction   Increasing aperture
Optical beam apodization
           
  Fresnel pattern distortion   Acoustic diffraction   Frequency plane filtering
Acoustic beam apodization
Material selection

Source: Isomet Corp. and Brimrose Corp. of America

Explore related content from Photonics Media




LATEST NEWS

Terms & Conditions Privacy Policy About Us Contact Us

©2024 Photonics Media