Ever hear of a one-way mirror?jms4 said:I would like to know if their are any materials that would allow light to pass in only one direction, In electricity we have diode, which will allow electricity to pass in only one direction, in optics how do we reflect light from one side and allow light from the other side to pass through?
Oh. I knew it was much more effective if the one room was much darker but I thought there was SOME asymmetry. Wrong again, huh? Well, thanks for the correction.jbriggs444 said:A one-way mirror is one way only because the room on the back side is darkened. There is no asymmetry in the ability of a partially silvered mirror to pass light in one direction or the other.
physmath said:Optic isolator, widely used in fiber optic systems, is a directional device made based on polarizing and rotating light polarization. If there's material with polarizing surfaces, its proper bulk might be the material you are asking?
There is a microwave equivalent to the optometrist isolator and that is the Circulator and Isolator - which again dump power from one direction into a load.Khashishi said:To be clear, the optical isolator based on Faraday rotation will absorb light going in the "wrong" direction, not reflect it. It gets absorbed in the polarizers. If you could reflect the light in one direction only, you would have a Maxwell's demon.
Actually, it's not like that in practice. A 'One way mirror' that you see in use consists of a pattern (strips, usually) of normal mirror with alternate gaps. The way it works relies on the fact that the (observation) room, behind is kept dark so that all the 'observed' can see is the bright reflections. There is no reflecting surface on the observer's side so they just see the light admitted through the gaps. The ratio of thicknesses of mirror strips to gaps can be what you want. If you choose 10% 90% ratio then you will get 10% back and it will pass 90%. But 90% of the light from behind the screen will get through in the other direction, through the holes. Nothing more is possible, as Khashishi has said.jms4 said:One way mirror is a semi reflecting mirror which allows 50% of the light to pass through and allows the other 50% to reflect back,
I think a circular polariser will do this, if located above a mirror. This is because the reflected light is opposite-hand polarisation and is reflected from the polariser.jms4 said:Thank you all for your replies,
First, let me tell the whole thing,
1. I need a material which would allow light to only pass in one direction
2. In one side it would allow the light to pass through
3. In the other side, it should reflect the light back, not absorb it,
One way mirror is a semi reflecting mirror which allows 50% of the light to pass through and allows the other 50% to reflect back, I need something like at-least 90-10%, which allows 90% to pass through and reflects 10% back, ideal(100%) is not possible, so something like around 80-90% would be fine.
tech99 said:I think a circular polariser will do this, if located above a mirror. This is because the reflected light is opposite-hand polarisation and is reflected from the polariser.
Yes, agree.sophiecentaur said:From your description, there seems to be a mirror in the way which would stop any light getting through in one direction (?).
When we say that light travels only in one direction material, it means that the material has the property of being optically anisotropic. This means that the speed of light in the material is different depending on the direction of travel. This is in contrast to isotropic materials, where the speed of light is the same in all directions.
In anisotropic materials, light travels along the direction of the material's optical axis. This is determined by the crystal structure of the material and can vary based on the direction of travel. In some anisotropic materials, light can also travel at different speeds depending on the polarization of the light.
Some common examples of anisotropic materials include crystals such as quartz, calcite, and tourmaline. Liquid crystals, which are used in LCD displays, are also anisotropic materials. Additionally, some polymers and biological materials, such as muscle fibers, can exhibit anisotropic properties.
The direction of light can have a significant impact on its behavior in anisotropic materials. For example, in birefringent materials, the speed of light can vary depending on the direction of polarization. This can lead to effects such as double refraction, where a single incident ray of light is split into two rays with different paths.
Anisotropic materials have a wide range of applications in various fields such as optics, electronics, and biology. They are commonly used in polarizers, waveplates, and other optical components. In electronics, anisotropic materials are used in liquid crystal displays and other devices. In biology, anisotropic materials play a crucial role in the structure and function of tissues and cells.