Pulsed laser diode driver - how it works?

In summary, the conversation is about a possible mistake in a data sheet for a pulsed laser diode driver. The person posting believes there is an error in the direction of the electron flow shown in the circuit diagram. They have attached the circuit and provided their explanation for how it works. They are hoping for confirmation from others that the data sheet is incorrect. Another person agrees with their explanation and they discuss the flow of electrons in a regular diode. The conversation also touches on the commercial product associated with the data sheet.
  • #1
McKendrigo
26
0
Hi everyone,

I've been looking at the data sheet for a pulsed laser diode driver that I've been using, and I've managed to convince myself that there's a mistake. I was hoping that if I post my explanation of how the circuit shown in the data sheet works, that you guys can either confirm that the data sheet is wrong, or (embarrassingly) tell me that I'm wrong :redface:

I've attached the circuit as shown in the data sheet. My explanation is as follows (which is more or less what the data sheet says):

When S1 is open, the capacitor Cpfn charges by the high voltage input, HV_IN, through the clamping diodes D1 and D2. The output laser diode is reverse biased in this case, so no current flows through it. When S1 is closed, D1, D2 and the output diode are effectively connected in parallel with the capacitor Cpfn. Because D1 and D2 are now reverse biased, and the output diode is now forward biased, all the charge that accumulated in Cpfn is discharged through the output diode, producing the output pulse from the laser diode.

Where I disagree with the data sheet is the direction of the arrow showing "electron flow". It shows the flow of electrons as moving from the output diode's cathode to it's anode. They seem to be depicting electrons flowing towards the negative terminals of the output diode and capacitor! Surely this arrow is pointing in the wrong direction...or have I got the wrong end of the stick?

Thanks in advance for your input!
 

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  • #2
At least in a regular diode the actual flow of electrons is from the cathode to anode, and that's also in agreement with your description of how the circuit works; i.e. the cap discharges through D3, with current flow in the direction of the arrow.
 
  • #3
Hi,

thanks for your reply. Glad to have someone agree with me! I'm still naive enough to have this voice in my head tell me that if it's in something like a data sheet, it must be right! ;)
 
  • #4
Hi,

Is there some commercial product according to this data sheet?
 
  • #5
Galiupatiket said:
Hi,

Is there some commercial product according to this data sheet?

Yes. It's from a commercial laser diode driver. The company is www.directedenergy.com and it's from a PCO-7110 Laser Diode Driver Module.
 

FAQ: Pulsed laser diode driver - how it works?

What is a pulsed laser diode driver?

A pulsed laser diode driver is an electronic device that provides the necessary electrical current to drive a pulsed laser diode. It is responsible for controlling the timing and intensity of the laser pulses.

How does a pulsed laser diode driver work?

A pulsed laser diode driver works by converting direct current (DC) into a pulsed current, which is then delivered to the laser diode. This is achieved through the use of high-speed switches that control the flow of current to the diode, allowing for precise control over the timing and duration of the pulses.

What are the key components of a pulsed laser diode driver?

The key components of a pulsed laser diode driver include a power supply, a pulse generator, a high-speed switch, and protection circuits. The power supply provides the necessary voltage and current to drive the diode, while the pulse generator controls the timing and duration of the pulses. The high-speed switch is responsible for switching the current on and off to create the pulsed output. Protection circuits are also included to safeguard the laser diode and the driver from potential damage.

What are the advantages of using a pulsed laser diode driver?

Pulsed laser diode drivers offer several advantages over continuous wave (CW) drivers. These include higher peak power output, shorter pulse durations, and better control over the timing and intensity of the laser pulses. This makes them ideal for applications that require precise control over the laser output, such as in medical procedures, laser rangefinders, and high-speed communication systems.

What are some common uses for a pulsed laser diode driver?

Pulsed laser diode drivers are used in a variety of applications, including laser spectroscopy, laser micromachining, laser printing, and laser radar. They are also commonly used in medical procedures such as laser eye surgery and skin treatments. Additionally, they are used in military and defense applications, such as target designation and laser weapons.

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