"lossless" optical waveguide - loss floor in glass media

[jim bell]

    On Friday, September 13, 2019, 03:59:39 PM PDT, coderman <coderman at protonmail.com> wrote:  
 
‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Friday, September 13, 2019 10:44 PM, Punk <punks at tfwno.gf> wrote:
....
>
> I guess we'll have to wait and see if some company specifically tries 'your' idea...

>i have to admit a side bet in this race:

>the US Patent office keeps a register of "classified" | "SECRET" | "TOP SECRET" inventions. if you, as an independent inventor, discover such a thing you find yourself bound by national secrecy law...

>but they take this track if they think it will be an effective cudgel.

>Jim takes no shit - the record is unequivocal. so I think Jim gets silence, but also not really a patent - a patent in public, but overridden by a national security imperative.

>(the collection benefit of using very low loss fiber is pretty self evident :)

Well, so far they have granted at least two of my patents concerning low-loss optical waveguide, so it is by no means secret. Isotopically altered optical fiber - Bell James Dalton
Isotopically altered optical fiber      a pdf to the '401 patent

Isotopically altered optical fiber - BELL JAMES DALTON 

I am slightly aware of what you speak:  granting a patent yet keeping it secret.  While in prison, unlike most "jailhouse lawyers" who just learn criminal and appeals law,  I intentionally learned a lot of many kinds of (Federal) law:   Contract, tort, libel, patent, anti-trust, copyright, etc.    I learned a lot of technical information because the LEXIS law library computer system that I occasionally had access to (replaced tons of books) was easily searchable.   
At one point, I became aware that the toxic war chemical VX had been invented and patented in about 1950, but that patent had been kept secret for many years thereafter.  In fact, I think the patentor was actually FMC, "Food Machinery Corporation"!!!!

http://www.nationalacademies.org/hmd/~/media/Files/Report%20Files/2007/Long-Term-Health-Effects-of-Participation-in-Project-SHAD-Shipboard-Hazard-and-Defense/VXNERVEAGENT.pdf


For example, in about 2008, I found a patent lawsuit between Corning and Sumitomo on the subject of Sumitomo's fluorine-doped cladding optical fiber.  https://casetext.com/case/corning-glass-works-v-sumitomo-elec-usa

I learned a great deal about optical fiber just by reading a legal case on this lawsuit, and its appeal.  
Here's a sampling:


By the mid-1960's, worldwide efforts were ongoing to develop long-distance lightwave transmission capability. In particular, the British Post Office sought an optical waveguide with an attenuation of 20 db/km, the approximate transmission efficiency of the copper wire commonly used in telephone communications.

B. The '915 Invention

Corning's work on optical waveguides began in 1966, when it was contacted by the British Post Office. Drs. Robert D. Maurer and Peter C. Schultz, working at Corning, developed the world's first 20 db/km optical waveguide fiber by early 1970. That achievement was due, in part, to the development of a fiber with a pure fused silica cladding and a fused silica core containing approximately three percent by weight of titania as the dopant in the core. It was also due to the careful selection of the core diameter and the RI differential between the core and the cladding.




Dopants are chemicals added to another material (here, fused silica) to alter one or more of its properties (here, the RI). The effect of the titania was to increase the RI of the core.

Bell Laboratories confirmed the attenuation measurements of Corning's fibers and considered Corning's achievement an important breakthrough, making long-distance optical telecommunications possible. Dr. Maurer first publicly reported the achievement of a 20 db/km optical  waveguide fiber at the Conference on Trunk Telecommunications by Guided Waves held in London, England. That announcement created enormous interest and was the subject of many articles in both technical and general publications. The inventors' advancement in technology won them accolades from various societies and institutes, for which they were presented with many prestigious awards and honors. In addition, the invention of the '915 patent has achieved impressive commercial success on a worldwide basis. The district court determined that "[t]he 915 patent clearly covers a basic, pioneering invention." 671 F. Supp. at 1377, 5 USPQ2d at 1551.





The '915 patent discloses a fused silica optical waveguide fiber capable of limiting the transmitted light to preselected modes for use in optical communication systems. Specifically, such a fiber is disclosed as having a doped fused silica core and a fused silica cladding (doping optional), wherein the RI of the core is greater than that of the cladding. Prior to the filing date of the application for the '915 patent, the inventors had experimented with dopants which increased the RI of fused silica, e.g. titania, and the '915 specification mentions only such positive dopant materials. At the time the application was filed, the inventors did not know of specific dopants that would decrease the RI of fused silica, although it had been known in the art since 1954 that the introduction of fluorine decreases the RI of certain multicomponent glasses.

C. The '550 Invention

Corning's titania-doped fibers required heat treatment to reduce attenuation to an acceptable level. An undesirable result of that treatment was a lowering of the mechanical strength of the fibers. Consequently, Corning sought to develop a low attenuation fiber which did not require heat treatment. In 1972, Drs. Maurer and Schultz found a solution in doping a fused silica core with germania, which also had the advantage of transmitting more light than using titania.

D. The '454 Invention

Corning recognized that when optical waveguide fibers were produced by flame hydrolysis, they contained hydroxyl ions. The residual hydroxyl ions absorbed light at certain wavelengths used in optical communications and, if they remained, would increase the attenuation of the fiber at those wavelengths. Working at Corning, Dr. Robert D. DeLuca invented a process to overcome this inherent problem by introducing a chlorine-containing drying atmosphere into the furnace during the "consolidation" phase.

E. District Court
Corning is the assignee of the three patents at issue. SEI and its subsidiaries, SERT and SEUSA, are engaged in the manufacture and sale of optical waveguide fibers. This appeal involves two suits which were consolidated: an action by SERT seeking a declaration of invalidity and noninfringement of Corning's '915 and '454 patents with a counterclaim by Corning alleging SERT's infringement of those patents, and a suit by Corning against SEUSA and SEI asserting infringement of the '915, '550, and '454 patents.
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