i thought this was a reply to another post :?

i thought this was a reply to another post :?

It was, but it was totally off topic in that other post, so it was moved.

Anything in particular you want to discuss about the laser?

Yes actually, is 532nm the best for the human vision? what does the W actually mean , other than a 1000 milli watts, is it the heat? i mean a watt refers to a joule and a joule refers to a newton and a newton refers to a law of motion ....

 

i mean to say what makes it defined as 1W to a 300mW(without linking 5 separate equations), im guessing its essentially the concentration of light? and maybe something related to infra red (when talking about carrying heat) not the wattage.

 

im thinking of doing some research into robotics and lasers for a dissertation, such as creating basic images on a wall or reacting to sound input. cheers.

A watt is a Joule of energy per second. So a 1 watt laser delivers 1 Joule of energy to the surface you point it at every second. A 1 watt light bulb uses 1 Joule of energy every second to make light.

Yes actually, is 532nm the best for the human vision? what does the W actually mean , other than a 1000 milli watts, is it the heat? i mean a watt refers to a joule and a joule refers to a newton and a newton refers to a law of motion ....

 

 

The eye is most sensitive (light adjusted) at around 555 nm. So a given amount of light energy will appear brightest if it's at that wavelength; 1 Watt has a Luminous flux (or power) of 683 lumens. At other wavelengths it is smaller, meaning it does not appear as bright.

 

http://en.wikipedia.org/wiki/Luminous_efficacy

Mains electricity is so much higher. Isn't it possible to have a 250W (mains 'lec in UK, not sure about the US) homemade laser? That sounds ridiculously dangerous.

Mains electricity is so much higher. Isn't it possible to have a 250W (mains 'lec in UK, not sure about the US) homemade laser? That sounds ridiculously dangerous.

 

or carry a ghost buster backpack around with a car battery in it?

 

i dont want anything dangerous. I want something portable but essentially i want to create a mechanism that controls the lasers precision, ive seen some awesome videos on youtube of people building personal laser displays with mirrors, balloons and bass but i wanna try program my own stuff and do alot more with it.

 

also what scientifically constrains the power a laser can output?

Mains electricity is so much higher. Isn't it possible to have a 250W (mains 'lec in UK, not sure about the US) homemade laser? That sounds ridiculously dangerous.

Mains electricity is 240 Volts in the UK and 120 in the US. That merely indicates the energy per unit of electrical charge in the electricity; it has nothing to do with how many watts of power the resulting laser consumes. (Although, if you plug a laser made for a 5V power supply into a 500V one, it will put out 100 times the power... very briefly, before something important melts.)

 

also what scientifically constrains the power a laser can output?

Heat is a big problem. Lasers are not particularly efficient, so a lot of the power you put in just goes to heat. You have to cool the system effectively if you want it to run for any significant period of time.

okay i understand. what about the diode im guessing they have a limit? and how is a laser any different from a normal light, is the light just concentrated or amplified?