How to improve the lifespan of laser diode module

How to improve the lifespan of laser diode module

Dec 18, 2019

The life expectancy of laser diode module depends largely on operating conditions.

The application determines the lifetime and performance required of the laser diode. A suitable PLD and drive electronics can be selected based on these requirements.

If the laser diode temperature continues to rise exceeding the maximum operating temperature, the diode can be damaged or the long term performance may degrade significantly. If the laser diode’s operating temperature is reduced by about 10 degrees, the lifetime will statistically double.

1. You must ensure the laser diode has an adequate heat sink for the waste heat produced. A simple method for determining the amount of waste heat is to take the total input power (Amps*Voltage=Input Power Watts) minus the optical output power (Watts). The balance is the watts of max waste heat. Depending on the semiconductor laser type and wavelength, laser diodes are typically 10 – 60% efficient at converting electricity into light. This heat is generated within a small area, it is critical that the laser is securely connected to an adequate heartsick.

2. Operating Temperature – Most lasers have a recommended operating temperature and a location where this temperature is measured. If the laser is operated at a temperature higher than recommended, the lifetime of the laser is reduced exponentially as the operating temperature is increased above the recommended temperature. Diode laser degradation accelerates with increased temperature. For many laser diodes, operating at a temperature lower than recommended can slightly increase the output power (higher efficiency) and/or improve lifetime.

Laser module lifetimes can be extended significantly by maintaining the case temperature at the low end of the operating temperature range. Heat sinks are recommended and must be used if the laser is operating constantly. Operating the laser modules at the low end of the recommended voltage range will also help to extend the lifetime of the laser.

Elite laser module with heatsink and TEC High Stability Lasers provide sufficient cooling. An air-cooled heatsink can maintain an operating temperature a few degrees above your ambient temperature. If the ambient temperature changes, so do the heatsink temperature. This temperature change will not provide stability of the laser wavelength and output power. Most often, active cooling of the heatsink must be used. Actively cooled heatsinks offer much better heatsinking performance and introduce temperature control into the system (TEC’s). The design of TEC which allows coolant to flow thru the heatsink, which will ensure the best performance and longest lifetimes.

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