High pressure-temperature conditions can be readily achieved through the laser-heated diamond anvil cell (LH-DAC). A stable laser source is required for reliable in situ measurements of the sample, as the sample is small with a thermal time constant of the order of microseconds. Here, we show that the power instabilities typical of CO2 gas lasers used in LH-DAC's are ±5% at the second timescale and ∼±50% at the microsecond timescale. We also demonstrate that the pointing instability of the laser requires either a diffuser or an integrating sphere for reliable total power measurements with small sized detectors. We present a simple solution for stabilizing the power of a CO2 gas laser on the second timescale by the direct modulation of the current across the tube and another solution that stabilizes the power to the microsecond timescale by externally modulating the CO2 laser beam. Both solutions can achieve a ±0.3% power stability.

中文翻译：

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用于 CO2 激光器功率稳定的光学和电子解决方案

通过激光加热金刚石砧座 (LH-DAC) 可以轻松实现高压-温度条件。需要稳定的激光源才能对样品进行可靠的原位测量，因为样品很小，热时间常数为微秒级。在这里，我们表明 LH-DAC 中使用的 CO2 气体激光器的典型功率不稳定性在第二时间尺度为 ±5%，在微秒时间尺度为 ±50%。我们还证明了激光的指向不稳定性需要扩散器或积分球，以便使用小型探测器进行可靠的总功率测量。我们提出了一种简单的解决方案，通过直接调制管中的电流，在第二个时间尺度上稳定 CO2 气体激光器的功率，以及另一种通过外部调制 CO2 激光束将功率稳定到微秒时间尺度的解决方案。两种解决方案均可实现 ±0.3% 的功率稳定性。