Measurement error analysis for polarization extinction ratio of multifunctional integrated optic chips.

Area of Science:

• Optoelectronics
• Integrated Optics
• Metrology

Background:

• Accurate measurement of the polarization extinction ratio (PER) is crucial for multifunctional integrated optic chips (MFIOCs).
• White light interferometry is a common technique for PER measurement, but susceptible to various error sources.
• Understanding and mitigating these errors is essential for reliable device characterization.

Purpose of the Study:

• To analyze and identify the primary sources of measurement error in PER determination for MFIOCs using white light interferometry.
• To develop and validate methods for reducing these errors to achieve high-accuracy PER measurements.

Main Methods:

• Analysis of three main error sources: axis-alignment angle (AA) of fiber connection, oriented angle (OA) of the polarizer, and birefringence dispersion.
• Theoretical calculations and experimental validation of error reduction strategies.
• Implementation of dispersion compensation techniques.

Main Results:

• Controlling AA within ±5° and OA within ±2° limits maximal PER error to under 1.4 dB (3σ uncertainty of 0.3 dB).
• Dispersion compensation effectively reduces errors, with variations analyzed against polarization-maintaining fiber (PMF) length.
• Experimental validation on a MFIOC showed a total measurement error of approximately 0.7 dB for a ~50 dB PER.

Conclusions:

• The proposed methods effectively reduce PER measurement errors in MFIOCs.
• Precise control of alignment angles and dispersion compensation are key to high-accuracy PER measurements.
• These findings facilitate reliable characterization of advanced photonic devices.