What were the welding torches for optics (part two)
This article is a continuation of the material devoted to the history of apparatus for welding optical fiber, which is was published in our blog earlier. Therefore, we are interested in diving under cat.
So the year 1980 seems to have been not so long ago, but if you look at the years through the prism of technology development, it seems that hundreds of thousands of years have passed. Then, in the first apparatus for welding optics, the operator had to examine the position of the fibers in a V-groove in a microscope and align them manually with screws. In many things everything depended on the experience and "curvature" of the hands of the master rather than on technique. This approach made it possible to achieve low losses when welding multimode fibers, but it was poorly suited for singlemode fibers.
As we noted in the previous publication, many realized that the development of a welding machine for single-mode fiber can become a separate business line and quite profitable. The development of such a device and engaged in many companies. Already by 198? Sumitomo introduced the device, with an integrated fiber alignment mechanism using a light source and a photodetector at the distal ends of each of the fibers to be welded.
According to the authors' intention, the light source and power meter should be installed at the distal ends of the fibers, i. E. at a distance of several hundred meters or even several kilometers from each other. With the help of the mechanism of the welding apparatus, the fibers moved and aligned along the core until the maximum radiation of light from the source was recorded on the meter. Of course, this idea of combining fibers required too much preparation and time and was not further developed, but the idea itself was subsequently modified and applied in the Siecor apparatus.
Let us now consider some of the remarkable models of the devices of the twentieth century that were not mentioned before.
One of the first models, about which there is almost no mention.
A - Handles for moving the fibers along the Z axis.
B - Electric arc power regulation (a certain value is selected, which depends on the type and the manufacturer of the optical fiber, in particular).
В - Switch "manual-automatic mode". In manual mode, the operator positions the fibers before and during the welding process.
In automatic mode, during the welding process, the machine itself reduces the fibers to each other - the fibers come into contact and abut each other with a given pressure.
D - Switch on microscope illumination.
D - Power on.
If the welding was done correctly and turned out to be of high quality, then the weld or any defect should not be visible in the microscope.
The main characteristics:
Alignment of fibers with a V-groove, automatic fiber cutting during welding;
Average losses during fiber welding:
- multimode - ??? dB
- single-mode - ??? dBK
Control of welded fibers on the projection microscope screen
Tensile test of welded fiber;
Weight less than 2 kg.
In this machine it was necessary to manually set the positions of the fibers (in the photo, the person turns the screw regulators with his thumbs), sniping out the position of their ends within the vertical band on the lens.
Fujikura FSM-10B (1983)
Together with the apparatus there is a separate module of the stove - tube heater.
Fujikura FSM-20C (1987)
Starting with this model, all power supply units are integrated inside the device (the external stove has become more massive, but with a 220 V connector). On the device itself, the power button became three-mode. There was a choice between power supply for a constant voltage of 12 V and a variable 220 V.
It is able to weld fibers that preserve the polarization state (PM), single-mode fibers (SM), multimode fibers (MM)
Actual average loss: ??? dB for SM and ??? dB for MM.
Through this tiny screen you can see the process of welding fibers
Welding of fibers on the machine FSM-20C
After 3 years, the FSM-20CS model was released for a multimode with a larger conventional folding screen (true black and white) and a stove built into the machine, and three years later, the legendary Fujikura 30 was developed and released in the mid-nineties.
The devices of Ericsson
Engineer Uwe Betcher, working for Sieverts Kabelverk (which later changed its name to Ericsson Cables, and later to Ericsson Fiber Optics) developed a number of welding machines. In the late 1990s, about 800 units were sold per year. Welding machines Ericsson were considered competitors to the best welding machines of the world at that time. Uwe Betcher and his team have developed many models: FSU 79? FSU 80? FSU 82? FSU 83? FSU 85? FSU 900 and FSU 905.
December 1? 1979 - model FSU 790was developed.
This is the first Ericsson welding machine (with fixed v-shaped ditches for multimode fibers). It was used in field tests for splicing the first Swedish optical fiber installed in Stockholm. Was released in a single copy.
December 1980 - model FSU-800was developed.
Became the first Ericsson device to enter commercial sales. About 100 apparatuses were produced.
1985 - Ericsson Ericsson FSU 830was released.
It was Ericsson's first device for welding single-mode fiber. This device was once the industry standard, winning the British contract for the supply of equipment for the construction of networks. A total of several thousand such devices were produced.
June 1986 - the model FSU 900was released.
The first model with the alignment of fibers by the method of thermal imaging.
Apparatus Fitel S141 (1986)
The British device Tritec FASE II
A compact welding machine with a microscope weighing only 2.5 kg. Provides connection loss of ??? dB (maximum 0.1 dB) for singlemode and multimode OB.
Contains a microscope with a magnification of 75 times.
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