what is optical activity?
455412
In optics, optical rotation or optical activity is the rotation of linearly polarized light as it travels through certain materials. It occurs in solutions of chiral molecules (e.g. sugar), solids with rotated crystal planes (e.g. quartz), and spin-polarized gases of atoms or molecules. It is used in sugar industry to measure syrup concentration, in optics to manipulate polarization, in chemistry to characterize substances in solution, and is being developed as a method to measure blood sugar concentration in diabetic people.
616971
A laser is composed of an active laser medium (gain medium) and a resonant optical cavity.\n\nThe gain medium transfers external energy into the laser beam. It is a material of controlled purity, size and shape, which uses a quantum mechanical effect called stimulated emission to amplify the beam. The gain medium is pumped by an external energy source, such as electricity or light (a flash lamp or another laser). The pump energy is absorbed by the medium, producing excited states. When the number of particles in one excited state exceeds the number of particles in some lower state, population inversion is achieved. In this condition, an optical beam passing through the medium produces more stimulated emission than the stimulated absorption so the beam is amplified. An excited laser medium can also function as an optical amplifier. \nThe light generated by stimulated emission is very similar to the input signal in terms of wavelength, phase, and polarization. This gives laser light its characteristic coherence, and allows it to maintain the uniform polarization and monochromaticity established by the optical cavity design.\nThe resonant cavity contains a coherent beam of light between reflective surfaces so that each photon passes through the gain medium multiple times before being emitted from the output aperture or lost to diffraction or absorption. As light circulates through the cavity, passing through the gain medium, if the amplification in the medium is stronger than the resonator losses, the power of the circulating light can rise exponentially.
101307
well, you kinda answered your own question. The laser optics refers (here) to the use of mirrors to focus the light on the sample, this is normally used for a fluorescent dye which has been used to stain a part of the cell.
208454
dunnerzplant pretty much has it right.  To give a more basic explanation, the retina has an array of "rods and cones" laid out like pixels on a tv screen, and they are all connected to the visual cortex that has a similar array of perceptive neurons that can piece all fo the signals together as a picture.\n\nDifferent cells in the retina have different chemicals that are sensitive to different colors, or wavelengths of light.  When light of that color strike that cell, the chemical does a slight shape-shift that ignites a mechanism to change the cell's output of neuroreceptors, liek a switch.  Once the light disappears, the photochemical shifts back to its latent state, and the perception of that color also ceases.\n\nIt's pretty cool stuff, really.  Any good Molecular and Cellular Biology textbook will give a good description of how the whole thing works.  I think even a basic college Biology text will give a rudimentary treatment of the subject.
937543
Bifocals and lightning rod.
1157696
An optical mouse is an ordinary wired mouse that happens to use a light beam rather than a roller ball to sense movement.\n\nA bluetooth mouse is a wireless mouse (bluetooth is a wireless technology).
615478
one that i have "seen" is a test for visual acuity using raman scattering of a laser.  \n\nthe scattered dots seem to "move" to an unfocused eye !\n\nalthough it cant be used to quantify visual acuity, it is a quick test if someone needs a vision prescription !
50035
Optical will be just fine.  Laser is almost overkill for your application, unless you are planning to be an architect or graphics artist?!
750439
amy is right.  this is the basis behind percieved perception.  what you see may be different than what somebody else sees however you speek of it as the same thing.\n\naarons answer is missing the part of transfering the light information into a chemical reaction inside the rod cells and then turn to electical activity.  this is where the possible problem occurs\nbetter yet heres the sequence \n\n1. Light rays enter the eyes by passing through the cornea, the aqueous, the pupil, the lens, the vitreous, and then striking the light sensitive nerve cells (rods and cones) in the retina.\n\n2. Visual processing begins in the retina. Light energy produces chemical changes in the retina's light sensitive cells. These cells, in turn, produce electrical activity.\n\n3. Nerve fibers from these cells join at the back of the eye to form the optic nerve.\n\n4. The optic nerve of each eye meets the other at the optic chiasm. Medial nerves of each optic nerve cross, but lateral nerves stay on the same side. The overlap of nerve fibers allows for depth perception.\n\n5. Electrical impulses are communicated to the visual cortex of the brain by way of the optic nerve.
875983
It's what you peer into. There's a diagram here:\n\nhttp://en.wikipedia.org/wiki/Optical_microscope
795692
the energy entering our eyes are a stream of photons, these energizes the "Rods & Cones" in our eyes. these in turn generate an appropriate electrical signal, which is carried to our brains by the optic nervs. the brain analyses the electrical signals and actually searches the immense database of pictorial references we all carry. we actually see the object in our brains. how this happens is still not fully explained. but this is proved that the energy from the photons are converted to electrical signals, another type of energy and transmitted to the brain
497685
In electronics, an opto-isolator (or optical isolator, optocoupler) is a device that uses a short optical transmission path to transfer a signal between elements of a circuit, typically a transmitter and a receiver, while keeping them electrically isolated — since the signal goes from an electrical signal to an optical signal back to an electrical signal, electrical contact along the path is broken.\nA common implementation involves an LED and a light sensor, separated so that light may travel across a barrier but electrical current may not.
560835
with travelling electrons.depending on their wavelength,colours are formed
865926
ok, classical symptoms of an optical mouse being used on a glossy colorful surface. Use it on a piece of cotton cloth, a napkin, a towel etc. That is the kind of surface you need to use it on.
791078
I suppose the answer is ultaviolet but as it is outside the visual spectrum of elctromagnetic radiation I can't see how you could define it as a coloUr.
478786
Your question is a good one, and you hit on the answer when you call it 'visual noise.'\n\nThe brain is a complex thing.  First off, vision is not a single 'sense' but more like a combination of related senses which work together.  That might seem odd, given that our eyes appear to do the hard work of 'seeing' things such that, without them, we're much worse off where vision is concerned.\n\nYour brain has a region called the 'visual cortex' which is located in the very back of your head.  This region is generally responsible for constructing images and making sense of what your eyes see.\n\nWhen you close your eyes, or enter a very dark room, suddenly there is no more information for your visual cortex to work with.  Its not quite like turning off a camera however.  \n\nYour brain is still quite active. It takes time for your brain to lower its activity.  What you are seeing are the after-images associated with all that former brain activity still playing itself out in your conscious awareness.  Your brain, suddenly starved for signals from your eyes, 'makes up' stuff to account for the small amount of accidental bio-electric activity that still remains.\n\nPerception and awareness are FAR less understood than the actual mechanics of visual stimulation.  Lots of people disagree on how we turn light and electricity/chemicals into mental pictures.  This process, and your perception of it, are still part of the great mystery of consciousness.
703477
eye = light \nears = sound\nnose = chemical