Wireless music transmission using lasers

[roz77]

Hey all. I'm currently working on a project where I use a laser to transmit music playing from my iPod. The laser is hooked up to the iPod through a circuit, and there is a solar cell that the laser is pointed at. There are two wires coming from the solar cell that are connected to a stereo cable. My problem is that the sound coming from the speakers is very quiet, and I want to build an op-amp amplifier for the signal. I've searched for some stuff online but I keep getting a bunch of different things. Can I just basically use a single signal amplifier for each channel separately? Or do I have to build a more complex circuit to handle both of the channels? Thanks for your help.

 

[berkeman]

Hey all. I'm currently working on a project where I use a laser to transmit music playing from my iPod. The laser is hooked up to the iPod through a circuit, and there is a solar cell that the laser is pointed at. There are two wires coming from the solar cell that are connected to a stereo cable. My problem is that the sound coming from the speakers is very quiet, and I want to build an op-amp amplifier for the signal. I've searched for some stuff online but I keep getting a bunch of different things. Can I just basically use a single signal amplifier for each channel separately? Or do I have to build a more complex circuit to handle both of the channels? Thanks for your help.

Could you please show more details for the transmitting and receiving circuits that you are currently using? That will help a lot in determining what else you should add at the receiver.

What power TX laser are you using, and how are you modulating its amplitude?

 

[skeptic2]

The laser is hooked up to the iPod through a circuit, and there is a solar cell that the laser is pointed at. There are two wires coming from the solar cell that are connected to a stereo cable. My problem is that the sound coming from the speakers is very quiet,...

Is your stereo cable connected directly to the speakers or does it go through an amplifier? If not you should try amplifying it before feeding it to the speakers.

I don't know the frequency response of solar cells. I've never seen it specified so I assumed it wasn't very good. If you lack high frequencies you may consider using a photo diode instead of solar cells. A photo diode doesn't produce current like solar cells, but merely varies its resistance in response to varying light levels. A photo diode may also be more sensitive than solar cells but you still will need an amplifier.