Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [laser-diode]

A type of diode that produces laser light.

A diode that producese laser light.

127 questions
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Optical audio transmitter can't handle speech

This is a question relating to my project on an optical audio transmitter. I wired up a very simple device in which I use an audio signal transformer (EI14) to modulate the intensity of a laser beam (a cheap 650nm, 5mW diode) according to the audio…
Piotr
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What makes a LED a laser diode?

High-level survey of this question is fine: After reading https://en.wikipedia.org/wiki/Laser_diode I still can't tell if the electronics that enable a diode to lase are different from those that enable it to emit light. So, in general, is a laser…
feetwet
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500mw laser diode: What's the point of a driver and will it need a lens to focus?

For a hobby project I recently bought a laser diode with the following specs: Mitsubishi 645-655nm 350-500mw High-Power Red Laser Diode LPC-836 Power output: CW 380mW Pulse Power: 570mW Working Current: <340mA Working Voltage: 2.2-3.0V Sealed…
Pedery
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What's the difference between a laser diode and ordinary LED?

What are the discerning properties that distinguish them; determining their different characteristics? In other words, I'm trying to do a compare / contrast: What do they have in common? How are they different?
voices
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Laser diode to remove copper layer from PCB

I used a DIY kit and made a PCB milling machine. So far I am happy with it but it is slow and the minimum thickness of the lines is depends on the tip's size. I want to replace the cutting bit with laser diode to ablate copper layer directly to…
dvdmn
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What is the purpose of a "monitor diode" inside a laser diode case?

I was looking for laser diodes to buy and I noticed many of them have a "monitor diode" included. What is the purpose of a monitor diode? Would not the current (of the laser diode) be a better way to monitor it?
Julio Otuyama
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Building a laser driver circuit?

I have a small laser diode I ripped out of a CD/DVD read write drive. It has 3 pins on it and my first question is what function does the third pin have? Is it a second ground? How do I go about determining the function of each pin safely without…
Shane Yost
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How can I make a constant current source for a CW laser diode?

I need to power a single CW laser diode with a constant current source. I have attached the datasheet of the laser. It is a 2.2-2.4V laser whicht operates at 80mA at full brightness. I see a lot of constant current circuits online but they all have…
leon bouman
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Can I simply adjust the output power of these laser diodes to meet my specifications? If so, then what are the consequences of doing such a thing?

I need a CW laser diode, with an integrated photodiode, with wavelength around 800nm and power 1-1.5mW. Although I didn't find anything that exactly matching my specifications, I did find this from Thorlabs and this from Roithner Lasertechnik.…
The Pointer
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How can I read the current from a monitor photodiode of a laser diode?

I bought a adl-65074tl-1 laser diode, I am trying to drive it and to read the feedback of the monitor photodiode with an oscilloscope. I am using a laboratory DC power supply and a multimeter for setting the voltage value of the diode to the 2.2 V…
G M
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Why do laser diodes need temperature controllers? Why not just cool them?

High quality laser diodes often require temperature controllers plus a "TE" (thermoelectric unit) that cool the diode and maintain it at a particular temperature using a Peltier cooler. Why not just cool the diode without a controller? Is there some…
Tyler Durden
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What's the difference between a FP, gain guided and DFB laser diode?

What is the difference between a Fabry-Perot (FP), a gain-guided and a Distributed Feedback (DFB) laser diode? I think Fabry-Perot is the default configuration, gain-guided has something to do with a strip electrode (but I'm not clear on how it…
Seanny123
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How to design an adjustable 5A current regulator with LM338?

I have recently taken interest in laser diodes, and I would like to drive one of them (NUBM08) without destroying it. Looking over the internet I learned there are many devices one can build to do this, one of which is called "linear regulator".…
RandomGuy
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Troubleshooting my own PCB

I have designed my own PCB and it doesn't work correctly. I needed to have a PCB that has only one push button to switch on and off a laser diode. The circuit does work kind of, but the laser diode only shines a little, it doesn't give the amount of…
leon bouman
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How to dim one of these cheap 5mW laser modules?

I used to have an old 3x LR44 lithium cell laser pointer for presentations. With the batteries slowly dying, the outputted beam also went dimmer. Recently I bought one of these cheap 650nm laser modules off eBay. They seem to be designed to work…
isync
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