Search results

Because such glasses are not intended to completely block all the light.

Since we aren't doctors go to your's. He or she can point you to a sleep clinic. Just for curiosity. Are you saying your social life is so active that you can't avoid devices that emit blue light just prior going to bed say two hours?

There's a possible easy solution you should have tried first. And that solution is stop using any device that you think emits blue light, such as a mobile phone, pc, tv a few hours before going to bed. This will allow melatonin to accumulate within your brain. P.S. I've read even moonlight can...

Looking forward to seeing what the divergence will be.

I was having fun with you. We members love to help those that have apparently done some homework. Your only option I think is a non diode pumped solid state (dpss) laser with a beam expander attachment. Green dpss don't like cold temps. Unfortunately it's not going to be inexpensive. Lasers in...

Well did you look? While I'm at it what's a "I don't wanna spend a lot"?

Have you looked for such a device?

What will be the focal length of the negative lens? What is the focal length of the lens in the photo?

Without knowing where the RL ends you'd be unable to know where the far field begins. In other words far field begins where the beam expands linearly. I forget how to easily multi-quote. Try this to see what happens. Place that lens a distance equal to the focal length from the diode.

In a reply yesterday to Alaskan and today the far field depends on where the beam starts to expand linearly. Before that the beam is in the Rayleigh Length (RL). Did you measure the RL?

Was your objective to focus or to achieve infinite conjugation (infinite focus)?

Any distance passed the Rayleigh Length which varies greatly. He's right. I think he mentioned 150m which would certainly be in the far field in this case.

Just Google: you'll read for yourself. Far Field isn't some random distance or vague term. Again Google.

Yes.

This single 75mm lens will function as a collimating if you place about 75mm from the diode.

Far field is defined as any distance beyond the Rayleigh Length. Which to be precise is the distance a beam expands 1.4 times its diameter at the aperture, with or without optics.

💕💕no💕💕 I've a question for you. What caused to think it possible?

The problem with using that is it dries comparatively slowly and may leave streaks. 70% definitely a no no.

Canned air for dust. If it's not dust on the lens then other methods using solvents is required. Google "how to clean laser optics" or this.

His objective is to focus a laser beam to a very small spot as I recall.