A study published inOptics and Laser Technology by researchers from the Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences, introduced a new theoretical model to analyze and suppress unwanted interference effects in multi-planar interface optical systems. This work addresses a critical challenge in the design of compact, high-performance optical devices used in fields like space exploration and satellite communications.

Modern optical systems increasingly rely on tightly stacked components, such as multiple optical filters, to achieve miniaturization and advanced functionality. However, this compact design makes them highly sensitive to environmental factors like temperature fluctuations and mechanical vibrations. These disturbances cause nanoscale changes in the gaps between components, leading to undesired interference that degrades image quality and measurement accuracy. Existing methods for interference suppression were often limited to specific scenarios and lacked a unified, system-level approach.

To tackle this issue, the research team developed a generalized theoretical model based on the Transfer Matrix Method. This model systematically characterizes how interference arises from the coupling of multiple reflections between layers and external environmental perturbations. It allows designers to input parameters like layer thickness, refractive index, and component spacing to quantitatively assess the risk of interference under various conditions. The team established a simulation model to visualize interference patterns and analyze the influence of key parameters.

The simulation results revealed that system stability is highly sensitive to nanometer-scale variations in the gaps between components. However, the team found that increasing the initial spacing between elements to a specific range, such as 1 mm, effectively suppressed interference by exceeding the coherence length of the light. Alternatively, modifying the effective refractive index of the multilayer films also disrupted the phase-matching conditions necessary for interference, providing another viable suppression strategy.

The researchers validated their model using multiple approaches. They analyzed spectral data from an on-orbit irradiance spectrometer, which exhibited clear interference fringes that changed over time due to thermal variations. Using a backup channel for calibration, they successfully corrected the data. Furthermore, they conducted ground-based experiments that physically adjusted spacings and filter orientations. The results confirmed that both increasing the gap and altering the effective refractive index significantly reduced interference, aligning closely with the model's predictions.

This study provides a practical and systematic framework for designing stable, high-performance multi-interface optical systems. By enabling engineers to identify and mitigate interference risks during the design phase, the model supports the development of more reliable miniaturized optical instruments for demanding applications in space and precision sensing.