Tower Optical’s Engineering Solutions: Stable Zero Order Waveplate Design for Extreme Temperature Conditions

By: Yoany Rodrguez PhD.

Crystal quartz glass is renowned for its remarkable coefficient of thermal expansion (CTE) stability, making it an ideal choice for applications requiring precision and reliability across diverse thermal conditions.

The CTE of crystal quartz typically ranges from approximately 5.5 to 10.5 x 10^-6 per °C over the temperature range of 0°C to 573°C. This inherent stability, rooted in the unique crystalline structure of quartz, ensures minimal variation in performance across temperature fluctuations.

At Tower Optical, we have leveraged this exceptional property to design innovative air gap zero waveplates featuring crystal quartz spacers. This design allows for a precise CTE match, mitigating the risk of deformation due to temperature-induced stress (Fig 1).

Fig 1: Zero Order Waveplate Air Gap using a Crystal Quartz Spacer.

The advantages of air gap waveplates lie in their ability to withstand high laser damage sources and compensate for the differential between both plates to maintain the design’s retardation. For further insights into this advantage, please visit our blog at https://toweroptical.com/advantages-of-air-gapped-waveplates/

Deviation in the optical structure can lead to shifts in retardation and transmitted wavefront error (TWE). At Tower Optical, we offer a reliable solution for high laser damage-coated waveplates, which, when combined with a crystal quartz spacer, provides an ideal solution for applications where Laser Damage Threshold (LDT) and temperature variation are critical factors. For detailed information, please refer to our blog:

https://toweroptical.com/new-high-laser-damage-program-for-zero-and-multiple-order-waveplates/

Our engineering team conducted a modulation process to validate the accuracy of previous calculations regarding retardation stability. Subsequently, through meticulous measurement processes, we demonstrated minimal retardation variation for half wave waveplate @632.8 nm, well within the tolerance range of +/- 0.005 waves, across temperatures spanning from -20°C to 50°C, as depicted in Figure 2. For detailed results, setup descriptions, and analysis methodologies, please reach out to Tower Optical’s Engineering Department.

Fig 2: Waveplate setup for temperature vs retardation analysis

While not standard catalog items, these custom waveplates are available upon customer request. Circular waveplates ranging from 10.0 mm to 101.6 mm and rectangular waveplates from 5.0 mm to 76.2 mm can be tailored to specific requirements.

For more information or to request a quote, please contact our team at Sales@toweroptical.com or call our office at 561-740-2525. At Tower Optical, precision engineering meets innovation, ensuring your optical needs are met with excellence.