What is the range of a 150mw, 300mw and 600mw laser for wavelengths 808nm and 980nm?
548925
Well in the 808 to 908 nm you are working in the range of photon emission of water.  I have not heard of a H2O laser yet; but, you never know...  I have seen some Noble gas lasers work near this frequency range however, most generate much higher power then the mw range you are querying about.\n\nAs to the range of a laser it really depends on the divergence of the beam.  The greater the beam spreads out from the end of the laser the less likely it will go far with any appreciable energy.  And example might be a Helium Neon at 6.15 um and 5 mw with a beam divergence of 1.5 radians.  Though visible at the target up to 1 mile away\nthe amount of energy is very small and can only be observed as a distant red dot.  That you have chosen a laser with a higher energy density (by a factor of about 10,000) you might be able to detect it at a distance of 100 miles as a small bluish dot regardless of the power level.  All the power level at this distance will do is determine the relative intensity of the blue dot, (IE faint, barely visible, clearly visible in a dark night sky.)  However, you would not be able to see the ends on the surface of the planet as the curvature of the earth limits the distance between two points at about 6 feet above the ground to around 14-15 miles.)\n\nThe other issue you have is how much interference there is between the laser and the target.  Indoors you can simulate long distances using fiber optic cables; however, most are tuned for higher frequencies.  Though Corning makes a 50nm single mode fiber that might be used to simulate a long distance; however as a general rule Bell Labs discovered the greatest distance they could send a high frequency signal through the fiber with a loss of less then one third the signal strength is around 160 miles.  In free air emissions there are a number of variables, dust or aerosols, rain, water vapor even the nitrogen in the air can attenuate the power of the laser.  Again Bell Labs did a number of experiments using laser to attempt to form a very tight communications channel between ground stations and satellites, they found it was possible; however, the interference was so great that even with 100 watts of a blue laser the signal would not allow a reliable signal.\n\nBut, I digress, if you want to calculate the db loss you have to know the signal loss of the medium the laser light will pass.  There are a number of tables that will help you estimate this data; but, you have to pay attention to the test conditions.  As a general rule you need to know the initial power, the attenuation of the medium and the minimum detection power required of the detector.  You have the initial power in your choices above, the minimum power of the detector will generally be around 10mw at this frequency.  So you only need to know the db loss of the medium.  The general rule of thumb is as you double the distance you reduce the energy level by the square root of the initial power.  So if you start with 100 mw at 1 meter you would be at 10 mw at 100 meters.  If you start with 1 watt you would normally reach 10 mw at 1000 meters.  If you start with 10 watts you would normally reach 10 mw at 10,000 meters.  All providing you do not have much interference.\nIf the medium has a db loss of 3db that means in addition to the squares rule you would have half the power or distance capability.  If you have 9db loss you would have about 1/8th the power level.  \n\nI don't know how much this will help you; but, these are general rules of thumb that should at least help you determine for yourself the type of data you might need to either do more research or guide you in your research.  \n\nGood Luck,\nDave Cooke
202169
LASER is the acronym for "Light Amplification by Stimulated Emission of Radiation".  It is, first, a process that is explained by quantum mechanics and statistical mechanics.  At this point, it has come into common use, and can also refer to either the light or the device used to produce this type of light.  It does not have a higher energy than light produced by other means, as the energy only depends on the frequency of light.  It does have a higher intensity concentrated into a smaller area, and much higher coherency than light from the sun or a light bulb.\n\nAlso, all light, regardless of how it is produced, travels at approximately 300,000 km/sec in a vacuum.  That value does not differ from one type of light to another, or one color of light to another.
644079
wavelength = speed/freqency \n=> (3 x 10^8)/(10^15)\nSo that is 3 x 10^-7 m\nor 3000 angstrom
51986
Are you referring to millimeter wave radar? I'm not familiar with any system that includes lasers.\n\nMillimeter wave radar is just radar of a particular band (somewhere between 30 GHz and 300 GHz). Some applications include cloud radar to detect the tops and bottoms of clouds; using doppler techniques to detect vertical movement within a cloud; and adaptive cruise control in cars to maintain a pre-set distance.
138258
try these sites: http://www.phy.ornl.gov/astrophysics/data/cf88/\n\nhttp://www.llnl.gov/science_on_lasers/07AstSpace/AS-F_Ther.html\n\nhttp://arxiv.org/abs/astro-ph/9801028\n\nI hope this helps....\n\nDon
1100966
OHP? Over Head Projector?\nUsually about 100W\nTherefore .1kW
279499
If you mean wavelengths, they vary widely from radio waves (at the low end) up to x-rays and gamma rays (at the high end).\n\nIf you mean "what are the wavelengths of VISIBLE light" here are their wavelenghts in nanometers (nm):\n\nred ~ 625-740 nm \norange ~ 590-625 nm \nyellow ~ 565-590 nm\ngreen ~ 500-565 nm \ncyan ~ 485-500 nm \nblue ~ 440-485 nm \nviolet ~ 380-440 nm
768677
Gallium based semi-conductor right now is too expensive to deploy. \n\nIf you want completely out of the left field, I'd go for optical processing.
895656
Hi. You could start here : http://www.mellesgriot.com/products/optics/oc_3.htm\nMay not be the best for everyone.
298698
You neglected to mention whether or not you are using led or laser.  Network or audio/video.  Too many variables to give you an answer.  But here is what we do everyday using 62.5 multimode fiber using a mode conditioner and a laser based transciever for gigabit network.  2500ft without a repeater. Our anolog video and audio is strictly db -loss restricted.  OUr budget is 20db so that would be about 15000 feet or so.\n\n\n\nSingle mode on the other hand can reach miles.  Wit the right laser I have heard of 78 mile shots.
173113
Below are some links with some cool diagrams.  I'm not sure if it's specifically what you wanted though.  The second link has some really cool information about spectral transitions in a LASER.
130222
The 200nm wavelength will have higher frequency; they're inversely proportional.\nThe 400nm wavelength will have less energy, as it has a lower frequency (and hence vibrates less often).\nAnd assuming you're talking about light - they both have the same velocity, c =~ 3.00 x 10^8 m/s\n\nIncidentally, 200nm is in the UV spectrum and isn't visible to people, while 400nm is a dark blue-violet.
1056339
There are a few items you will need:-\n1) A source of high voltage (to exicte the gas in your laser to emit photons). A readily availible item to do this would be the ballast (transformer) in a flourescent tube. This should get you up to between 700 to 1700 volts. It is preferabe if you have a supply closer to the upper end. This is dangerous so be sure to use appropriate precautions when working with high voltages.\n2) Choose the type of gas to excite. Gases to use include Carbon dioxide, helium, argon, neon, krypton - depending on the frequency you want from the laser. A nice big ruby could be used to make a really cool ruby laser - I could never afford to buy one though.\n3) build a laser tube - or better buy one from ebay. If you have glass blowing skills and make can make your own electrodes and embed them in the glass tube and make partial reflective mirrors on the end or the tube you can make one - but it's really tricky.\n4) fill your lser tube with the gas/gases you choose under reduced pressure.\n5) connect the electrodes to your power supply\n6) power it up....\nIt's as easy as that... uses the same basic principle to a flourescent tube, except that all the light from the partial reflector window is in phase.\n\nFor more detail I suggest you google something like "home made laser"
58422
A typical human eye will respond to wavelengths between 400 and 700 nm.  Some may be able to perceive from 380 to 780 nm.
60102
Sierra Pacific Infrared\n\nhttp://www.x20.org/
215329
You need a green- helium safe type- laser, a converter, an adapter. \nThe company heathkit/zenith used to sell them.\n \nAnd you need a lot of money to buy the equipment.
134128
The first working laser was made by Theodore H. Maiman in 1960[2] at Hughes Research Laboratories in Malibu, California, beating several research teams including those of Townes at Columbia University, and Arthur L. Schawlow at Bell Labs. Maiman used a solid-state flashlamp-pumped synthetic ruby crystal to produce red laser light at 694 nanometres wavelength. Maiman's laser, however, was only capable of pulsed operation due to its three energy level transitions. Later in the same year the Iranian physicist Ali Javan, together with William Bennet and Donald Herriot, made the first gas laser using helium and neon. Javan later received the Albert Einstein Award in 1993.