OldADC
Active Member
How is it substantially or materially different from a laser disc system? Is it a complete departure? It's hard to imagine how this would be an analog item. I'm not really sure the world is ready for another format. Seems like we're kind of burned out on all the format changes and that might be exactly why vinyl has come back.
To include Shrugg in this answer, no, this is nothing like laser disc. And I'll use this one to answer everyone else as well.
Not ELP, not LaserDisc, not designed to read existing vinyl. This would be an entirely new technique the details of which are dependent on X3 (can't type technical on this board so read that as Chi 3) the non-linear optical susceptability of a particular material. Exposure controls the induced change in the material and read back sees that change. Gents, I really don't wish to seem haughty or anything at all remotely like that as this business has always been a haven for some deeply fraudulent techno babble, but with PhD in Optics and Lasers and 24 years in designing lasers and optical systems for advanced defense applications, I have a few techniques in hand that have been proven and can be adapted to the task of analog recording.
The signal from the mixing board would modulate the laser, the laser would therefore modulate (through a Chi3 process) a material spin coated to a substrate. Readback would be accomplished via a laser diode illuminating the coated disc, the output of which would therefore be the modulated signal originally recorded. So it is pure analog. Anyone with a background in optical susceptibilities would immediately note that a Chi3 process is likely to yield modulation to the polarizability and therefore constrains the dynamic range to 90 degrees of polarization rotation. Two channels means that the net beam containing both information streams is a dynamic polarization ellipse and therefore easily read and deciphered back to a purely analog signal. It has also been shown as many as 40 years ago that the dynamic range of 90 degrees polarization rotation can be discerned down to 14 bit equivalent. That number is limited by the quantum noise (aka injection noise) of the photodetector. And photodetectors are WAY better than they used to be. I can buy photon counters (yep, detectors where the noise is so quiet they can reliably count single photons) for $50.
This brings us to Nat and Manfred's replies which are the most on point and present the greatest challenge. This requires a new physical media, likely about the size of a CD and able to contain about the same amount of music (roughly 40 min) in purely optical analog form. Writing a disc would be pretty close to the kind of process for mass production of CDs. You can dang sure write them way faster than you want to read them out. And the playback hardware would be good for only this. Simply laser diode as opposed to a fairly sophisticated laser to do the writing but it would all be optimized to read the OAR (Optical Analog Recording). Are there enough crazies out there to warrant the attempt?
I know you guys would pay $2k-$5k for the playback machine for your system. The bigger question is would you pay $40 for an OAR to get really pure analog recordings?
Nat and Manfred, good to hear from you guys again and thanks for chiming in. The last 6 yrs or so have been really difficult and busy as we in the high end laser business are reaching the long term goals of multiple 10s of kiloWatts for ship and airborne defensive systems. Directed Energy is going to work...it does work...but the physics are damn hard.