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  1. Xref: sparky sci.electronics:13535 rec.video:9722
  2. Newsgroups: sci.electronics,rec.video
  3. Path: sparky!uunet!munnari.oz.au!metro!sunb!macadam!johnh
  4. From: johnh@macadammq.edu.au (John Haddy)
  5. Subject: Re: Optically scanned TV (was Re: Blue Lasers)
  6. Message-ID: <1992Jul28.230043.12414@mailhost.ocs.mq.edu.au>
  7. Sender: johnh@macadam (John Haddy)
  8. Nntp-Posting-Host: macadam.mpce.mq.edu.au
  9. Organization: Macquarie University, School of Mathematics, Physics, Computing and Electronics
  10. References: <Bs26IL.GwE@news.cso.uiuc.edu> <1myx_6m@rpi.edu> <1992Jul28.123009.2910@ucsu.Colorado.EDU>
  11. Date: Tue, 28 Jul 1992 23:00:43 GMT
  12. Lines: 41
  13.  
  14. In article <1992Jul28.123009.2910@ucsu.Colorado.EDU>, weverka@spot.Colorado.EDU (Robert T. Weverka) writes:
  15. |> In article <1myx_6m@rpi.edu> ncc1701@acm.rpi.edu writes:
  16. |> >tmkk@uiuc.edu (Khan) writes:
  17. |> >
  18. |> >>I heard a brief tidbit in one of the popular media about (IBM?)
  19. |> >>inventing a blue laser, 
  20.  
  21. ... [stuff deleted]
  22.  
  23. |> >
  24. |> The Argon Ion laser is often used for blue.  One watt of optical power
  25. |> for onley $20,000.
  26. |> 
  27. ... and with only 0.01% efficiency, expect large electricity and water supply
  28. bills. (:-)
  29.  
  30. However, Ar+ lasers have dominant lines ranging from 454.5nm to 528.7nm. This
  31. range is not really "Blue". True blue is around 430nm. The shoreter wavelengths
  32. can be achieved with Ar++ (which is really in the near UV at 351.1nm and
  33. 363.8nm), Cd+ (441.6nm) and Sr at 430.5nm.
  34.  
  35. The quality of colour of a Sr laser has to be seen to be truly appreciated!
  36. Unfortunately, our He-Sr laser, being recombinant in operation, will only work as
  37. a pulsed source (5-10kHz). For projection TV use, this forms a slight problem -
  38. not fast enough to display 1 pixel per pulse, and pulse durations too short to
  39. display sections of a picture frame.
  40.  
  41.  
  42.  
  43. --------------------------------------------------------------------------------
  44. |                    #                       |
  45. |    johnh@mpce.mq.edu.au        #    School of Mathematics, Physics,   |
  46. |                    #        Computing & Electronics       |
  47. | John Haddy    ph  61-2 805 8959    #     Macquarie University NSW 2109    |
  48. |        fax 61-2 805 8983    #              AUSTRALIA               |
  49. |                    #                       |
  50. |                        =======================================|
  51. | Electronics Technical Services Group    <=TDM=>    High Speed Networks Group |
  52. |                                            V                                 |
  53. | Commonwealth Government Special Research Centre for Lasers and Applications  |
  54. --------------------------------------------------------------------------------
  55.