Fundamentally, a laser diode module incorporates a laser diode, one or more lenses, and drive electronics, packaged in a laser module housing. Laser modules are used in a wide range of applications from providing a visual guide for alignment applications to curing in 3D printing and enabling 3D measurement.
This blog post will discuss laser module lifetime, the factors that affect lifetime, and what manufacturers can do to maximize lifetime and minimize downtime.
Laser Diodes and Modules
A laser diode is a laser where the active medium is a semiconductor device. A laser diode is a specific type of light-emitting diode and its lifespan can be many years. In practice, the lifespan of a laser module will depend on how it is used in the application as well as aspects of the laser module design.
In certain applications, it can make commercial sense to choose a laser module incorporating a lower-cost laser diode, perhaps with a shorter expected lifetime, if the laser module can be easily replaced with minimal downtime, if the environment in which it will operate is not particularly demanding or if it will not be driven to maximum rated output power.
Laser Module Lifetime
With use, the efficiency of the laser diode will decrease. For a given current, the optical output of the laser diode will reduce but, in many cases, if the pin configuration of the laser diode is suitable and the laser diode package includes a monitor photodiode, the laser module will incorporate a driver that compensates for that. The laser diode itself will become less efficient but the driver will provide it with sufficient current to maintain the optical output. This is known as automatic power control.
ProPhotonix produces laser modules with power levels up to 500mW. Lasers at the higher end of this power range require excellent thermal management to maintain lifetime and performance.
There are many aspects of the laser module that determine laser module power. The design of laser drive electronics enables higher laser power. The capability of the laser diode is an important factor. Thermal management ensures that heat generated is conducted away from the laser diode and is critical in high-power lasers.
How to make laser modules last longer
Good thermal management is critical to maximizing laser life. With good thermal management, the heat generated is driven away from the laser diode thereby maximizing lifetime. Pulsing the laser module can also extend the in-service life of the laser module.
There are many factors that affect laser module lifetime including the laser diode selected, drive electronics, thermal management, and environmental conditions.