If laser power stability or wavelength stability is important to your application, cooling is a very critical aspect of your system design. Access Laser provides many different ways to cool the laser to achieve different levels of stability, optimizing for your specific requirements.
Real-world applications can vary vastly, so it is hard to quantify exactly how much improvement is achievable by changing from one type of cooling method to another. In the table below, we provide some general “rules-of-thumb” to indicate the levels of stability typically achieved by different means of cooling. (1 is better than 2.)
Explanation:
- This is for reference only.
- The lower the number, the better the stability.
- Different methods of cooling:
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- Fan Cooled: Fans can mounted to the laser in factory, or the customer can mount the fans away from the laser, and force airflow symmetrically on both sides of the laser.
- Water Cooled: Not just any water, but water from a precision chiller with temperature stability of ±0.1˚ C is required.
- Fan Cooled Closed-Loop: The laser body temperature is monitored and controlled by the closed-loop temperature controller, and cooled by fans. While significantly more stable than the open-loop case, this setup is still susceptible to air flow and large variations of temperature (±2˚ C) in the ambient environment.
- Water Cooled Closed-Loop: The laser body temperature is monitored and controlled by a precision chiller, such as Neslab model RTE-7 PLUS. Typically, the chiller is capable of ±0.1C and has an external sensing port for the temperature sensor built in the laser.
Cooling the laser symmetrically about its width is of vital importance. In addition to all the options above, we also provide Line Tracker. This is a closed-loop cavity-length control option with computer interface, which will further improve stability. There are many other methods to enhance stability, such as building a thermally insulated box around the laser, and we are always open to collaborative engineering work. Please feel free to call us to discuss your ideas.