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Questions tagged [laser-diode]

A type of diode that produces laser light.

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0answers
29 views

3d laser smoke projector [on hold]

I've discovered if you shake a green laser diode rapidly and blow smoke it creates an animation which is really cool. The problem is your arm gets tired fast right about when it starts looking really ...
1
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1answer
161 views

Driving a butterfly package DFB laser

I want to drive a DFB laser in a type-2, 14-pin butterfly package. The manufacturer has provided limited information on how to bias the laser diode and could not get any information on the reference ...
2
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1answer
127 views

How to understand this simple voice-over-laser circuit

The Sci-Toys project A simple laser communicator shows a surprisingly simple way to send an audio signal over a laser pointer. A transformer AC-couples an audio signal directly into the DC supply to ...
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0answers
83 views

Amplitude Modulating a simple Laser using an RF transformer

I know I can modulate a laser using an audio transformer see pic and website below. Pen Laser website I was wondering if it’s possible to modulate a simple pen laser using RF signals in the RF range ...
1
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2answers
115 views

Laser Diode Feeding

Edit: Laser diode info page I have a basic question about laser diodes. For a 14-pin butterfly package as shown below. I know that I need to control the current going in to the laser diode, but I don'...
3
votes
3answers
306 views

Why is a lab PSU not suitable for driving a laser diode directly?

I'm looking to drive some laser diodes (50mW) at very modest powers (50%), using simple circuits no doubt less sophisticated than most lab PSUs. Why does this site say it's not an option? I ...
0
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1answer
84 views

Laser pointer circuit

I've got a small red laser pointer from a chinese ultrasonic distance meter, which has a small regulator circuit (6mm x 7mm) with SMD components. I guess that is a constant current to drive the laser,...
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1answer
47 views

Bandwidth (Data rate) of a laser beam when no datasheet exists for the module

I ordered a large number of laser modules that look like the following: When inspecting mine with a basic multimeter, I noticed a 90 ohm smd resistor is fitted on the module. I see no other ...
1
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1answer
52 views

Can sending correct data via UART qualify as valid manchester encoding?

I'm currently in the process of having a laser beam detected by the phototransistor. While the parts in themselves work, I want to detect when the beam has been detected. I understand that a 38Khz ...
0
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0answers
52 views

Unused laser diode current amplifier in cd rom

I have unscrewed an old Cd Rom and now I'm trying to understand the circuit. The head that contains all the lens and laser has an EL6274CU current amplifier ic soldered on a flexible cable along ...
0
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1answer
53 views

Laser Diode Coherent OBIS

I was trying to change the laser diode in one of our broken OBIS Lasers (640nm, 40mW). Thus I thought I would buy this Thorlabs HL6362MG diode. If I connect the diode to a power supply directly at 2....
2
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3answers
654 views

How to transmit data with a laser beam? [closed]

I am working on a project about data transmission with lasers. The project is very young so I can modify my current planned setup if necessary. This is the actual planned setup: Every raspberryPi ...
0
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2answers
124 views

Laser driver configuration with 5MHz modulation and current monitoring

I have a huge task in front of me and I am actually lost. I want to drive this laser diode. I've worked with laser dirvers before and I used LM317 for simple circuits. This time I'd like to safely ...
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1answer
132 views

Laser for Engraving & Cutting [closed]

Can I use 500mw 808nm Infrared IR Laser Diode for engraving and cutting of wood, plastic and metal?ASER https://www.banggood.com/Focusable-500mw-808nm-Infrared-IR-Laser-Diode-Dot-Module-12V-TTL-Fan-...
1
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0answers
116 views

Max current for 5ns pulsed CW laser diode?

I'm looking to reduce the cost of a lidar system by replacing the DPSS laser with a blue pulsed laser diode (this is for an underwater project) Is there a rule of thumb for the appropriate current to ...
20
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4answers
3k views

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 ...
21
votes
1answer
2k views

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 (...
0
votes
1answer
325 views

What is current modulated laser driver? What does it do to the laser?

The title is actually one of the many questions I have. I've started to work on a project that includes lasers. I've worked with lasers and fiber optics before and I even constructed a simple constant ...
3
votes
3answers
106 views

Improving the quality of 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 output of my phone. The ...
0
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2answers
788 views

Simple constant current regulator for a 1.6A laser LED

My intent is to build a simple driver for a laser LED with an operating voltage of 4.6 volts and forward current 1.6 amps. I have some spare LM317s that I would like to use, however they can supply 1....
0
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2answers
390 views

What are the advantages of pulsed laser

I'm talking about laser diode for engraving/cutting cnc. As far as I know led or laser diodes are often driven by pulse signals to enhance their performances. Please note I'm not talking about the ...
1
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1answer
367 views

Influence of active area of photo diode on sensitivity

I am using a photodiode for detecting the laser. I have a question regarding the active area of the photodiode. Is less active area photodiode is less sensitive? Or it totally depends on the laser ...
0
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2answers
165 views

Protecting laser diode that is transmitting an audio signal

I would like to first state that I do not really know anything about circuit design- I am very much a beginner. That being said, I am working on a project where I am using a laser to play music. I ...
0
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1answer
159 views

Importance of laser numerical aperture in selecting photo diode

I want to design a circuit in which the laser light will be detected by a photodiode. I just wanted to know how the laser numerical aperture will affect the photodiode selection. Am I have to ...
0
votes
2answers
986 views

Constant Current Source using Fixed Voltage Regulator

I was in the process of building a 2W laser diode driver and I realized after some debugging that I had a 3.3V constant voltage LM1086 chip instead of an adjustable voltage regulator. I intended to ...
0
votes
1answer
201 views

Microcontroller controlled pulse current source

I want to make the laser (Iop < 20mA and Vop < 2.5V) blink with help of MicroController. I made the following circuit and tried to test it using a 10k resistor instead of the laser in order to ...
0
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3answers
257 views

Relationship between optical power and drive current/voltage?

For a project I'm working on I've got a laser diode whose spec sheet lists the optical power and operating voltage of the module. Unfortunately, the parameter I need most is the drive current. Can the ...
0
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1answer
85 views

Remove glass top from a TO can packaged VCSEL

I have a VCSEL packaged in a TO-46 can (image here / datasheet with package dimensions). I need to remove the glass top – with or without the silver-coloured cylinder – without damaging the laser ...
1
vote
1answer
262 views

lower current than expected through simple circuit powering laser diode

I have a circuit I designed for a raspberry pi to turn a laser off and on. I designed it to supply approx 22mA but it's barely getting 11mA. I've tried numerous tests but I can't figure out what's ...
1
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1answer
67 views

Laser 'receiver' for MCU

I need to send data over a wireless link, not far - max 50m. I have plenty of laser diodes, 1-5mW, with glass lenses that can be adjusted. I would rather avoid buying a 'receiver', since I can ...
4
votes
3answers
420 views

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 ...
0
votes
1answer
353 views

Trying to find transistor needed for laser security alarm

so I'm building a laser security alarm circuit for a class project and I need a transistor, but I'm having difficulty figuring out what type to get to allow the circuit to switch ON/OFF once light is ...
2
votes
1answer
282 views

Characteristics of a Laser Diode Below Threshold

This question is related to that one: Can laser diode be operated with lower than specified voltage? I am driving a laser diode in a current controlled fashion. What actually happens below the lasing ...
2
votes
4answers
349 views

What communication protocol does this pinout match? DATAP, DATAN, CLKP, CLKN, CLKSEL

I am trying to build a laser diode driver circuit using a part from Analog Devices. (The datasheet is here for your reference: http://www.autex.spb.su/ad/ADN2848.pdf) It appears that there are 4 data ...
0
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0answers
73 views

Individually modulate two lasers diodes using sound - while using the same power suppy and preventing signal “bleed over”

I'm trying to individually modulate two lasers diodes using the same power supply. The modulation for each laser module is created by the left and right audio channels. Is there a way to do this ...
4
votes
4answers
2k views

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 ...
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1answer
3k views

How to determine the operating voltage and current of a laser diode?

I have harvested several laser diodes out of old 16X to 22X DVD writers. I used a driver circuit based on LM 317 but I was not able to reach the lasing current of the diode. I do not have the specs ...
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2answers
935 views

What determines a laser's strength?

What specification of a laser will cause a laser to be more "powerful" over another more specifically in cutting capabilities? If multiple, is there one that increases the strength more than the ...
0
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2answers
93 views

Extreme Fiber Coupled Laser Diode Power Loss Causes

What could cause a laser source with fiber coupled laser diodes to have extreme loss of power? The laser diodes have a wavelength of 658nm and have an output rated at 60mW but it seems as though the ...
0
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2answers
306 views

Help designing a circuit to drive a 1550nm DFB LD and use it to modulate an RF signal

I need to modulate an RF signal (random sine wave acting as data) using the 1550nm DFB Laser Diode, I need a control circuit to drive the Laser Diode and inject the data to modulate the LD carrier ...
2
votes
1answer
938 views

DIY laser range-finder

I would like to develop a laser range-finder board similar to Extech DT300. I would like to achieve a centimeter precision at 20 meters. I don't know if devices such as DT300 use a "standard" time-of-...
0
votes
1answer
114 views

Identify this electronic component from DVD drive [closed]

I got this component from an old laptop dvd drive. It was placed within the laser assembly. Could you tell me what this component may be?
0
votes
1answer
208 views

Powering a laser pen

I have recently started tinkering with technology to see how things work. I am building a small box with a phone charger, flashlight and solar panel however I wanted to add a laser pen. After taking ...
1
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1answer
131 views

Decreasing voltage ripple across current sense resistor

If you ever checked constant current/constant voltage sources such as LT8613 or LT8611, while reading datasheet you probably encoutered such sentence: Care must be taken and filters should be ...
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1answer
177 views

How should I use this laser diode from eBay?

I am new to lasers. I have some 5mW pointers, but thats it. I want to have something more powerful, and I happened to find this 50mW laser diode with driver: http://pages.ebay.com/link/?nav=item.view&...
0
votes
1answer
395 views

Common Cathode Laser Diode - Photovoltaic photodiode

I have a pretty quick question. I am working with a laser diode with an integrated photodiode. The pin configuration has a common cathode connection for bother the laser and photodiode. I want to ...
0
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1answer
302 views

Measure the output voltage of photodiode in parallel with a laser diode

Since a photodiode and the laser diode is connected in parallel in a laser device, measuring the voltage across the photodiode can tell us how much power the laser is emitting. The photodiode and ...
0
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3answers
201 views

detecting laser using solar cell and band pass filter

I need to detect a laser signal using a solar cell. My first problem is that all I get is a current generated from the solar cell that will vary (as I understand and correct me if I'm wrong) in it's ...
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1answer
289 views

Adjust the power of laser diode on both CW and pulsed mode

I am working on my graduation project to build a laser unit, i am supposed to control the power of laser diode when operating in pulsed mode and continuous mode. firstly, i had the pulses from "...
1
vote
1answer
2k views

What's the difference between Laser Diode, LED and Lasers? [closed]

I'm struggling a bit with this. I know LEDs are built using semiconductors, but a diode is a also a semiconductor right? So, Laser Diodes are not essentially the same as LEDs?