矽光子積體電路（PICs）被認為是構建大規模光學資訊處理系統的關鍵技術。如今，數以千計的矽光子元件可以整合在單一晶片上，展現了在光學領域中進行複雜處理的能力，例如同調奈米光子學光學神經網路（ONNs）與量子資訊處理。因此，PICs 被視為一項具有前景的技術，適合大規模生產，並有潛力以較低的成本實現高產能製造。
目前，可程式化的 PICs 引起廣泛關注。透過這些可調元件的應用，越來越複雜的干涉系統得以擴展，其產生的干涉效應有助於推動如大規模量子閘等突破性發展。因此，光子學中的可程式化 PICs，類似於光學領域的現場可程式化閘陣列（FPGAs），有潛力推動多種應用，提供緊湊、低成本、低功耗且高度彈性可重組的設備。
與傳統為特定應用所設計的光子電路不同，可程式化 PICs 可透過軟體於運行時重新配，進而動態改變光路，並精準控制波導的相位以實現不同功能。然而，為達到精確的路徑重組與相位控制，需即時監測光路中所有或特定波導的光學相位。這點至關重要，因為基於干涉效應的光子元件本身容易受到相位誤差影響，且對環境溫度變化極為敏感。
在本研究中，我們提出一種新型裝置架構，將微機電系統（MEMS）光學探針整合至由可調馬赫–曾德爾干涉儀（MZI）構成的矽光子積體電路中，用以診斷可程式化光子積體電路中的相位誤。

Silicon photonic integrated circuits (PICs) are recognized as an essential technology for building large-scale optical information processing systems. Today, thousands of silicon photonic components can be integrated into a chip, which has demonstrated the ability to perform complex processing in the optical domain, such as coherent nanophotonic optical neural networks (ONNs) and quantum information processing. Thus, PICs stand out as a promising technology for large-scale production, offering high manufacturing volumes at potentially low costs.
Nowadays, programmable PICs are attracting significant attention. As more complex interferometric systems are scaled up using these tunable components, the resulting interferences can enable groundbreaking advancements, such as large-scale quantum gates. Consequently, programmable PICs in photonics, akin to optical field-programmable gate arrays (FPGAs), have the potential to drive a wide range of applications, offering compact, low-cost, low-power, and highly flexible reconfigurable devices. Unlike conventional photonic circuits designed for specific applications, programmable PICs can be reconfigured at runtime through software, enabling the dynamic rerouting of optical paths and precise control of waveguide phases to implement various functions. However, achieving accurate rerouting and phase control requires real-time monitoring of the optical phase across all or selected waveguides in the circuit. This is crucial because interference-based photonic components are inherently susceptible to phase errors and are highly sensitive to environmental temperature fluctuations.
In this research, we propose a new device scheme for integrating microelectromechanical-system (MEMS) optical probes on Si photonic integrated circuits constructed by tunable Mach–Zehnder interferometers (MZI). This device scheme can be utilized to diagnose phase errors in programmable photonic integrated circuits.