Can anyone answer this Physics question?

[daddy_4_eyes]

I got this SAC for my yr12 physics class, and i have this question that i'm getting different answers for.

At what wavelengths do red lasers operate in?

People at school as well as some books say 620-680nm, other books say 470-500nm.

I'm stuck, can anyone help me?

 

[jefffff34]

cheating on year 12

All right then, who has any idea what the hell LOGARITHMICS are?

 

[daddy_4_eyes]

Re: cheating on year 12

Originally posted by Hoggy
All right then, who has any idea what the hell LOGARITHMICS are?

Its a reasearch project so it isn't cheating. Like the saying goes "copy one person and you're cheating, copy 2 and you're researching"

 

[Visro]

Well I recently did atomic physics for school but I didn't cover laser light. If its red laser light wouldn't it be at the same wavelenght as red light?

 

[daddy_4_eyes]

Originally posted by Visro
Well I recently did atomic physics for school but I didn't cover laser light. If its red laser light wouldn't it be at the same wavelenght as red light?

Same logic I used. Here's a table from a book i have:Wavelength (nm) Colour absorbed Colour observed
380-420 Violet Green-yellow
420-440 Violet-blue Yellow
440-470 Blue Orange
470-500 Blue-green Red
500-520 Green Purple
520-550 Green-yellow Violet
550-580 Yellow Violet-blue
580-620 Orange Blue
620-680 Red Blue-green
680-780 Purple Green

Going by that, red light is 470-500nm. But a fair few books dispute it and say its 620-680nm. This table basically got me stuck, as the colour observed means the colour we see, right?

 

[ant]

I'm not exactly sure but I know that red light has a wavelength of 6.2 x 10-7 m. which is 620 nm I think. Hope that helps.

 

[Visro]

My text book says a wavelength of about 650 nm. Around 600-700 nm then.

 

[eagleskickass]

Wait till the end of next year and I'll tell you, only doing year 11 physics at the moment. At least I understand what your saying though!

 

[Mooster7]

There are different kinds of lasers, and I don't know exactly what you mean by "red" lasers. I don't think you are talking about infrared lasers (like CO2 lasers).

If you mean a ruby laser (which is a red laser, and the 1st type BTW) it operates at 694 nm.

The red lasers which are used as "pointers" or the ones that kids take to the WWF operate at frequencies between 630 - 680 nm.

Peace

Mooster

 

[Mooster7]

Also, there is a Helium Neon Laser which operates at 633 nm.

Anything lower than that, and you are operating in the UV, Blue and Green ranges. Therefore, the book which gives figures in the 400-500 ranges are either

A) Wrong
B) You have misinterpreted it
C) I am getting too old for this *****.

Peace

 

[Nic]

While we're on this topic, does anyone want to sit my specialist maths exams? Pretty please?

 

[BomberBoy]

Originally posted by Nic
While we're on this topic, does anyone want to sit my specialist maths exams? Pretty please?

Do ya trust me?