# Cheap laser pen quality?

1. Aug 26, 2010

Hello- On places like eBay and Amazon, one sees a lot of ultra-cheap, under $15 laser pointers in various colors. For example, my favorite green astronomy laser cost me twenty dollars from amazon last year. Contrast these prices with laser pointers from more respected brands, which seem to range in price from$100-$300 dollars. What exactly is one paying for here? Do the more expensive, brand name models have some attributes that make them better for certain purposes? For example, when shopping for my astronomy laser I considered a$105 Orion, but I settled for a $17 Hong-Kong-sketchy model that seems to work just fine and be as bright as I need it to be. I am currently shopping for a violet or UV spectrum laser, and I am again tempted to just get something cheap. 2. Aug 29, 2010 ### Redbelly98 Staff Emeritus If you are talking about green pointers, then I would guess the cheap ones are not lasers but LED's -- and the expensive ($100 or more) ones are indeed lasers.

If you want relatively cheap violet or uv, again I think you would need to use an LED rather than a laser.

3. Aug 29, 2010

### Bob S

What do you know about the LED polarization? Have you marked it on the side of your LED pencil pointer yet?

Bob S

4. Aug 29, 2010

### wil3

It behaves like a laser, and it travels an equivalent distance to a laser beam. I have worked with LEDs, and so I know what they look like. What makes you thing that it is just an LED?

5. Aug 29, 2010

### DaveC426913

I figure what made him think it is just an LED is the price. Was that not apparent?

6. Aug 29, 2010

### wil3

It's not an LED, so does anyone have any alternate opinions? I was thinking it had to do with pulse amplitude consistency or something. Thank you for your replies.

7. Aug 30, 2010

### Bob S

The space in my red laser pointer "pencil" is almost completely taken up by two AAA batteries. The rest is a solid state laser diode (probably 670 nM AlGaInP used in cheap red laser pointers). See:

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

Bob S

8. Aug 30, 2010

### Redbelly98

Staff Emeritus
As DaveC said, the price you quoted. Red laser pointers simply use red diode lasers; green laser pointers are more involved. But ... a quick google search does show green laser pointers in the $20-$40 range, so it looks like my reasoning based on price was flawed.