6

With those restrictions you will probably be stuck with using fibre optics, which are expensive. Something like the Parans SP3 system for example. Making your own by purchasing fibers is a possibility but still not cheap and there are a variety of problems with actually implementing it (such as focusing enough light into the fiber and controlling heat issues)...


5

Fiber cables have higher data transfer speed not because light travels faster in a fiber than electromagnetic waves in a copper wire, but because they can be modulated by signals having far higher frequencies than can be managed in the case of copper wires.


4

Considering your difficult geometry, you might look into solar panels above ground, with wires to the underground lights. This has the added advantage that you can store some of the energy in batteries for use when there is no sunlight at the surface.


3

If you increase the length of the fibre, you will get more reasonable results. The losses -in my mind- need to be distributed along the entire length of the fiber . Currently, you seem to model a very small portion of the fiber, and as such you have a very small area that need to transfer a seemingly small amount of energy. However, if that energy is going ...


3

If a model does not reflect reality, the model is not accurate enough for that situation. Consider some of the minutia in the workings of light. First an alternate model for the fiber: As light passes through, some of it passes straight through, some is "absorbed." (quotes because I suggest including reflection and refraction in here as well as ...


3

I really have no idea, but I did come up with the following possibilities. To minimize reflections from the instrument itself. Light reflecting off the endoscope could interfere with the doctor's view. Because little (if any) body tissue inside the body is black, thus making it easier to distinguish the instrument from body parts. Because that's the ...


3

CO2 lasers cannot be coupled into standard silica-based fibres, because these fibres absorb light longer than 2.1um. You could use hollow silica fibres, but they are quite recently developed, so might be expensive. Otherwise I‘d just go with the standard approach of free propagation over mirrors OR use a solid state laser which can be coupled into standard ...


2

Basically, materials have a tensile strength, and a yield strength. The latter describes how much it elongates under stress, the former how much stress it can have before breaking. It is always given in (M)Pa, so force per surface. This means it doesn't matter what shape or size your fibers are, it remains the same. All the material properties remain the ...


2

You could try adapting the litre of light principle, where a hole is made in the roof of a shed which is then plugged with a re-purposed 1.25 L soft drink bottle filled with water. It provides light in the interior of the shed while the sun is shining. If a bottle was fitted to both ends of a internally reflective plastic tube and the whole system was ...


2

As long as you are not sending data, any light input in one end should be detectable with a color filter covered light sensor at the other end. Example: green film for a green led/laser. Light at the sensor means the beam is not blocked, no light means it is blocked. No fancy modulation should be necessary unless you are trying to filter out similar ...


2

Although probably not what you are after, there is Power-over-fiber, which is a technology analogous to "Power-over-Ethernet". To be honest, I haven't seen any devices that take advantage of this capability, although this can be because fibre optics devices are not as common (?) as ethernet devices. The idea behind a PoF system is able to provide ...


1

Niels Nielsen's answer is correct. Just to provide some calculations as to actual propagation speeds (not signal bandwidth): Typical optical fibers have $n\approxeq 1.5$ , so the propagation speed is $\frac{c}{1.5}$ , or roughly 2E8 m/s . This is the field, or photon, speed. Using the formula from Wikipedia, the speed of electromagnetic waves in a good ...


1

Your assumption on temperature increase is flawed You can't convert watts to temperature directly unless the object is perfectly insulated and the application of heat has a limited time. The equation from your link would result in a temperature increase directly proportional to time, increasing forever. Temperature is a measure of "heat content," ...


1

After the exchange of comments, (more specifically) that the glass is transparent, my "guess" is the following: You state that the signal power loss is in the order of 1 W. Assuming the measurement system before and after can accurately measure the energy difference, this power drop can be attributed to the following things: increasing the energy ...


1

It depends on the your requirement but yes power can be transmitted through optical fiber. Optical Power can be transmitted through optical fiber like laser diode but the power efficiency is also comparatively low around 50-60%. The advantage is that for smaller distances the propagation loss is almost negligible. Although an insulated copper wire is a ...


1

Shorter wavelengths get you into the microwave regime, i.e. use air or vacuum for the "fiber core." Back to optical comms, then: Much of the design parameter space does depend on available material for the fiber and the driving lasers (absorption loss vs. wavelength is a major concern). And there are "holey fibers" which in fact have an ...


1

You want both a laser that is easy to make and a material that can transmit that laser with low losses (transparent) and is also easy to make. Also, for a gut feeling, 1THz is starting to become like a radio wave. Think about how radio waves seem to like to spill everywhere rather than stay confined inside a material. Also, shorter wavelengths make the ...


1

A pulsed laser is defined via the difference between phase and group velocity - the frequency $f_{ceo}$ - and the repetition frequency of the pulses - $f_{rep}$. In the frequency domain (because the pulses are following each other in time with frequency $f_{rep}$), the spectrum is a line spectrum since it is the Fourier transform of arbitrarily thin pulses ...


1

There is not necessarily any relationship between the two. In theory, a pulsed laser could exist without exhibiting a frequency comb spectrum, and a frequency comb could exist without operating in pulsed mode. Your confusion probably arises because one has a discrete set of pulses in the time domain while the other has a discrete set of 'pulses' in the ...


1

Fiber optics depend on the surface reflecting light by total internal reflection. Therefore the properties of the outer surface are crucial, and reflection depends on what your understanding of a "stream" is. If the water is in direct contact with anything solid (or liquid) (most likely anything but air), it will not work. Total internal reflection depends ...


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