How To Protect Your Laser Diodes From Electrical Damage

How To Protect Your Laser Diodes From Electrical Damage

Electricity is necessary for many different applications, but it can often be unruly, even damaging equipment if you’re not careful. This damage can be disastrous, especially when dealing with something as fragile and precise as a laser diode. The slightest issues can lead to the diode being unstable, interfering with the application it’s a part of. Continue reading to learn how you can protect your laser diodes from electrical damage.

How Does Electricity Damage Laser Diodes?

The first step to understanding how to protect your laser diode from electrical damage is to conceptualize how electricity damages these diodes in the first place. In a laser system, you have electricity coming in. These charged particles run through the system, eventually releasing energy through photons inside the laser itself in the form of coherent light. From that point, many researchers and physicists will use the laser light for diverse scientific and engineering applications. However, what’s common between these applications is that the laser must be stable and accurate.

Unfortunately, electricity can be tricky. Voltage fluctuations can happen at any point due to the power grid, and those same fluctuations can occur and disrupt the laser diode. With the average appliances, these fluctuations can present themself as:

  • Flickering lights
  • Unstable charges
  • Tripping in the circuit breaker
  • Sparks coming from an outlet
  • Overly bright lights
  • Connectivity issues

These problems aren’t fun to deal with, but they are manageable and generally fixable. However, even the smallest voltage fluctuation can cause significant problems with laser applications, leading to current spikes and electrostatic discharges. Laser diodes are sensitive, and these spikes and discharges can interfere with the goal of the laser application. These fluctuations interfere with this short-term application and potentially damage the diode and its ability to function accurately in the future.

Symptoms of Damage

One of the tricky parts about reducing electrical damage with your laser diodes is that you may not notice damage has happened. Many of these voltage fluctuations and the corresponding current spikes and electrical discharges are similarly difficult to see, but their aftereffects are glaring. Some common symptoms you may notice after electrical damage occurs are:

  • Difficulty focusing
  • Failure to lase
  • Shifts in the current threshold
  • Changes in beam-divergence
  • Reduced output power
  • Erratic changes in temperature

These are common signs that your laser diode has sustained damage, but thankfully, there are steps you can take to protect against these electrical variances in your laser system.

Take Care of Your Instrumentation

The first step to protecting your diodes from electrical damage is properly controlling your instrumentation. When people work with laser diodes, they use many more instruments than just the diode—they’ll typically use diode drivers, temperature controllers, and laser diode mounts. All this equipment keeps the diode safe and accurate, but there can be issues if they do not work as intended.

For example, it’s relatively easy for people to use the wrong equipment, calibrate something incorrectly, or have a piece of equipment lose effectiveness over time. When this happens, it’s easy for your laser diode to experience the following:

  • Power-line surges
  • Transients
  • Overheating
  • Over-current

Finding a current source you can control is crucial, and many laser diode drivers offer this. You’ll need to find the right one for your laser diodes, but most provide a constant current source, are linear, and low noise. In addition to a driver, you’ll need a temperature controller to adequately compensate for temperature fluctuations.

Controlling the temperature of a laser diode is necessary to ensure it doesn’t overheat. Temperature controllers become even more important when you realize that lasers can heat up quickly. Some temperature controllers can accommodate microscopic temperature variances, while others are lower precision and work better with more general applications. Without working equipment like drivers and temperature controllers, it’s easy for electrical damage to compound and disrupt the laser diode’s functionality.

Find the Right Mount

Another important step you can take to lower the risk of damage to your laser diode is finding the proper mount. Mounts are essential for any laser diode setup because they help keep the lasers stable and can reduce interfering noise. Laser diodes come in several different types of packages, and you must accommodate those different packages with your mount. You must find the appropriate mount that is correct for your unique laser diode applications.

Carefully Mount Your Laser Diode

After finding the proper mount, it’s time to connect your laser diode. For these applications, picking a new laser diode eliminates outside variables such as age and existing damage. After receiving your laser diode package, it’s vital to let it sit for a few hours and achieve thermal equilibrium. Once it’s ready, ensure that the equipment you use, including clean gloves, tweezers, and everything else around you, is grounded. Electrostatic discharges (ESD) can quickly damage the diode in this stage if you’re not careful.

In addition to making sure the environment is grounded, you should also eliminate dust and other particulates that can contaminate the diode. Be sure to use the right hardware and, if required, the correct amount of grease when mounting. It’s easy to use the wrong screw, which could damage the diode or mount, or contaminate the setup with too much grease.

After performing all these actions, you can make the electrical connection. The connection between the diode and mount must be secure, so always use appropriately sized connectors and wires, and make sure to tighten everything properly. Improper connections will damage the diode and interfere with any applications they’re a part of.

Laser diodes are incredibly fragile, and if you want to protect them from electrical damage, you must be very careful. Accuracy is critical in laser operations, and electrical damage can dramatically interfere with this accuracy, but thankfully, you can do things to stop this damage from happening. The minimization of handling these diodes is important, as is the type of mount you use, and at Arroyo Instruments, we are here to help. We have all kinds of laser diode holders that you could ever need to minimize electrical damage in your laser diode setup!

How To Protect Your Laser Diodes From Electrical Damage