Pulsed multiple colour laser system

Abstract

A pulsed multiple colour laser system is disclosed having particular application for incorporation into a digital holographic printer for producing RGB colour reflection holograms. A Nd:YLF crystal ( 1 ) in a laser cavity is excited to produce an emission at (1313) nm which is frequency converted by doubling to 656.3 nm and by tripling to 437.7 nm. In a separate cavity a similar Nd:YLF crystal ( 1 a ) is synchronously or asynchronously excited to produce an emission at 1047.1 nm (or at the related line of 1053 nm) which is frequency converted by doubling to 523.6 nm (or 526.5 m). The emissions at 437.7 nm and 656.5 nm are combined co-linearly with the emission at 523.6 nm (or 526.5 nm) to produce a single RGB pulsed laser beam.

1 - 50 . (canceled)  
   
   
       51 . A pulsed multiple colour laser system comprising: 
 a first active laser element provided in a first laser cavity, said first active laser element comprising Nd:YAG and wherein said first active laser element is arranged to generate laser radiation at a first fundamental frequency;    means for arranging the laser mode within said first laser cavity to be single longitudinal mode;    means for frequency doubling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency doubled frequency;    means for frequency trebling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency trebled frequency;    a second active laser element provided in a second laser cavity separate from said first laser cavity, said second active laser element comprising Nd:YAG and wherein said second active laser element is arranged to generate laser radiation at a second fundamental frequency;    means for frequency doubling said laser radiation at said second fundamental frequency to provide laser radiation at a second frequency doubled frequency;    means for arranging the laser mode within said second laser cavity to be single longitudinal mode;    a flashlamp for flashlamp pumping said first active laser element; and    a flashlamp for flashlamp pumping said second active laser element.    
   
   
       52 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein said laser radiation at said first fundamental frequency has a wavelength of 1318.8 nm.  
   
   
       53 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein said laser radiation at said first frequency doubled frequency has a wavelength of 659.4 nm.  
   
   
       54 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein said laser radiation at said first frequency trebled frequency has a wavelength of 439.6 nm.  
   
   
       55 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein said laser radiation at said second fundamental frequency has a wavelength of 1064.2 nm.  
   
   
       56 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein said laser radiation at said second frequency doubled frequency has a wavelength of 532.1 nm.  
   
   
       57 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein the output of said pulsed multiple colour laser system comprises: 
 laser radiation at said first frequency doubled frequency;    laser radiation at said first frequency trebled frequency; and    laser radiation at said second frequency doubled frequency.    
   
   
       58 . A pulsed multiple colour laser system as claimed in  claim 51 , further comprising an active or passive Q-switch provided in said first laser cavity.  
   
   
       59 . A pulsed multiple colour laser system as claimed in  claim 51 , further comprising an active or passive Q-switch provided in said second laser cavity.  
   
   
       60 . A pulsed multiple colour laser system as claimed in  claim 51 , further comprising means for arranging a laser mode within said first laser cavity to be TEM 00 .  
   
   
       61 . A pulsed multiple colour laser system as claimed in  claim 51 , further comprising means for arranging a laser mode within said second laser cavity to be TEM 00 .  
   
   
       62 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein said first and second active laser elements are provided either: (i) in separate ring oscillators; (ii) in separate linear cavities; or (iii) with one active laser element in a ring oscillator and one active laser element in a linear cavity.  
   
   
       63 . A pulsed multiple colour laser system as claimed in  claim 51 , further comprising a Nd:YAG amplifier.  
   
   
       64 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein said means for frequency doubling said laser radiation at said first fundamental frequency is provided within said first laser cavity.  
   
   
       65 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein said means for frequency trebling said laser radiation at said first fundamental frequency is provided within said first laser cavity.  
   
   
       66 . A pulsed multiple colour laser system as claimed in  claim 51 , wherein said means for frequency doubling said laser radiation at said second fundamental frequency is provided within said second laser cavity.  
   
   
       67 . A pulsed multiple colour laser system as claimed in  claim 51 , further comprising means for combining said laser radiation at said first frequency doubled frequency, said laser radiation at said first frequency trebled frequency and said laser radiation at said second frequency doubled frequency into a co-linear or non co-linear laser beam.  
   
   
       68 . A master write holographic printer comprising a pulsed multiple colour laser system, said pulsed multiple colour laser system comprising: 
 a first active laser element provided in a first laser cavity, said first active laser element comprising Nd:YAG and wherein said first active laser element is arranged to generate laser radiation at a first fundamental frequency;    means for arranging the laser mode within said first laser cavity to be single longitudinal mode;    means for frequency doubling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency doubled frequency;    means for frequency trebling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency trebled frequency;    a second active laser element provided in a second laser cavity separate from said first laser cavity, said second active laser element comprising Nd:YAG and wherein said second active laser element is arranged to generate laser radiation at a second fundamental frequency;    means for frequency doubling said laser radiation at said second fundamental frequency to provide laser radiation at a second frequency doubled frequency;    means for arranging the laser mode within said second laser cavity to be single longitudinal mode;    a flashlamp for flashlamp pumping said first active laser element; and    a flashlamp for flashlamp pumping said second active laser element.    
   
   
       69 . A hologram copying device comprising a pulsed multiple colour laser system, said pulsed multiple colour laser system comprising: 
 a first active laser element provided in a first laser cavity, said first active laser element comprising Nd:YAG and wherein said first active laser element is arranged to generate laser radiation at a first fundamental frequency;    means for arranging the laser mode within said first laser cavity to be single longitudinal mode;    means for frequency doubling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency doubled frequency;    means for frequency trebling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency trebled frequency;    a second active laser element provided in a second laser cavity separate from said first laser cavity, said second active laser element comprising Nd:YAG and wherein said second active laser element is arranged to generate laser radiation at a second fundamental frequency;    means for frequency doubling said laser radiation at said second fundamental frequency to provide laser radiation at a second frequency doubled frequency;    means for arranging the laser mode within said second laser cavity to be single longitudinal mode;    a flashlamp for flashlamp pumping said first active laser element; and    a flashlamp for flashlamp pumping said second active laser element.    
   
   
       70 . A pulsed multiple colour laser system comprising: 
 a first active laser element provided in a first laser cavity, said first active laser element comprising Nd:YLF and wherein said first active laser element is arranged to generate laser radiation at a first fundamental frequency, wherein said laser radiation at said first fundamental frequency has a wavelength of 1313 nm;    means for arranging the laser mode within said first laser cavity to be single longitudinal mode;    means for frequency doubling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency doubled frequency, wherein said laser radiation at said first frequency doubled frequency has a wavelength of 656.5 nm;    means for frequency trebling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency trebled frequency, wherein said laser radiation at said first frequency trebled frequency has a wavelength of 437.7 nm;    a second active laser element provided in a second laser cavity separate from said first laser cavity, said second active laser element comprising Nd:YLF and wherein said second active laser element is arranged to generate laser radiation at a second fundamental frequency, wherein said laser radiation at said second fundamental frequency has a wavelength of 1053 nm or 1047.1 nm;    means for frequency doubling said laser radiation at said second fundamental frequency to provide laser radiation at a second frequency doubled frequency, wherein said laser radiation at said second frequency doubled frequency has a wavelength of 526.5 nm or 523.6 nm; and    means for arranging the laser mode within said second laser cavity to be single longitudinal mode.    
   
   
       71 . A pulsed multiple colour laser system as claimed in  claim 70 , further comprising a flashlamp for flashlamp pumping said first active laser element.  
   
   
       72 . A pulsed multiple colour laser system as claimed in  claim 70 , further comprising a flashlamp for flashlamp pumping said second active laser element.  
   
   
       73 . A pulsed multiple colour laser system as claimed in  claim 70 , wherein the output of said pulsed multiple colour laser system comprises: 
 laser radiation at said first frequency doubled frequency;    laser radiation at said first frequency trebled frequency; and    laser radiation at said second frequency doubled frequency.    
   
   
       74 . A pulsed multiple colour laser system as claimed in  claim 70 , further comprising an active or passive Q-switch provided in said first laser cavity.  
   
   
       75 . A pulsed multiple colour laser system as claimed in  claim 70 , further comprising an active or passive Q-switch provided in said second laser cavity.  
   
   
       76 . A pulsed multiple colour laser system as claimed in  claim 70 , further comprising means for arranging a laser mode within said first laser cavity to be TEM 00 .  
   
   
       77 . A pulsed multiple colour laser system as claimed in  claim 70 , further comprising means for arranging a laser mode within said second laser cavity to be TEM 00 .  
   
   
       78 . A pulsed multiple colour laser system as claimed in  claim 70 , wherein said first and second active laser elements are provided either: (i) in separate ring oscillators; (ii) in separate linear cavities; or (iii) with one active laser element in a ring oscillator and one active laser element in a linear cavity.  
   
   
       79 . A pulsed multiple colour laser system as claimed in  claim 70 , further comprising a Nd:YLF amplifier.  
   
   
       80 . A pulsed multiple colour laser system as claimed in  claim 70 , wherein said means for frequency doubling said laser radiation at said first fundamental frequency is provided within said first laser cavity.  
   
   
       81 . A pulsed multiple colour laser system as claimed in  claim 70 , wherein said means for frequency trebling said laser radiation at said first fundamental frequency is provided within said first laser cavity.  
   
   
       82 . A pulsed multiple colour laser system as claimed in  claim 70 , wherein said means for frequency doubling said laser radiation at said second fundamental frequency is provided within said second laser cavity.  
   
   
       83 . A pulsed multiple colour laser system as claimed in  claim 70 , further comprising means for combining said laser radiation at said first frequency doubled frequency, said laser radiation at said first frequency trebled frequency and said laser radiation at said second frequency doubled frequency into a co-linear or non co-linear laser beam.  
   
   
       84 . A master write holographic printer comprising a pulsed multiple colour laser system, said pulsed multiple colour laser system comprising: 
 a first active laser element provided in a first laser cavity, said first active laser element comprising Nd:YLF and wherein said first active laser element is arranged to generate laser radiation at a first fundamental frequency, wherein said laser radiation at said first fundamental frequency has a wavelength of 1313 nm;    means for arranging the laser mode within said first laser cavity to be single longitudinal mode;    means for frequency doubling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency doubled frequency, wherein said laser radiation at said first frequency doubled frequency has a wavelength of 656.5 nm;    means for frequency trebling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency trebled frequency, wherein said laser radiation at said first frequency trebled frequency has a wavelength of 437.7 nm;    a second active laser element provided in a second laser cavity separate from said first laser cavity, said second active laser element comprising Nd:YLF and wherein said second active laser element is arranged to generate laser radiation at a second fundamental frequency, wherein said laser radiation at said second fundamental frequency has a wavelength of 1053 nm or 1047.1 nm;    means for frequency doubling said laser radiation at said second fundamental frequency to provide laser radiation at a second frequency doubled frequency, wherein said laser radiation at said second frequency doubled frequency has a wavelength of 526.5 nm or 523.6 nm; and    means for arranging the laser mode within said second laser cavity to be single longitudinal mode.    
   
   
       85 . A hologram copying device comprising a pulsed multiple colour laser system, said pulsed multiple colour laser system comprising: 
 a first active laser element provided in a first laser cavity, said first active laser element comprising Nd:YLF and wherein said first active laser element is arranged to generate laser radiation at a first fundamental frequency, wherein said laser radiation at said first fundamental frequency has a wavelength of 1313 nm;    means for arranging the laser mode within said first laser cavity to be single longitudinal mode;    means for frequency doubling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency doubled frequency, wherein said laser radiation at said first frequency doubled frequency has a wavelength of 656.5 nm;    means for frequency trebling said laser radiation at said first fundamental frequency to provide laser radiation at a first frequency trebled frequency, wherein said laser radiation at said first frequency trebled frequency has a wavelength of 437.7 nm;    a second active laser element provided in a second laser cavity separate from said first laser cavity, said second active laser element comprising Nd:YLF and wherein said second active laser element is arranged to generate laser radiation at a second fundamental frequency, wherein said laser radiation at said second fundamental frequency has a wavelength of 1053 nm or 1047.1 nm;    means for frequency doubling said laser radiation at said second fundamental frequency to provide laser radiation at a second frequency doubled frequency, wherein said laser radiation at said second frequency doubled frequency has a wavelength of 526.5 nm or 523.6 nm; and    means for arranging the laser mode within said second laser cavity to be single longitudinal mode.