A differential delay line for optical coherence domain polarimetry

Abstract

We propose an optical delay line based on differential structure for improving measurement accuracy and extending scanning length of optical coherence domain polarimetry (OCDP). The differential delay line is composed of two independent graded refractive index lenses (GRIN) and a double-faced mirror. The OCDP measurement model with loss coefficient and measurement error caused by the GRIN-lens-based delay line is discussed. Compared to the general optical delay line based on a single GRIN lens, the fluctuation of the loss coefficient of differential delay line is reduced to ± 0.1 dB with scanning range of 0.8 m, which corresponds to 80% improvement.

Distributed bonding interface characterization of composite laser crystal based on optical low-coherence reflectometry

“…The main components that occupy instrument volume and are prone to losses are the optical delay line and the fiber probe. The former can be addressed with mature technologies such as differential delay lines [22] , so there is no need to worry about it. However, the losses caused by the fiber probe need to be carefully considered.…”

“…Conversely, OLCR achieves continuous spatial scanning through a moving reflective prism and can achieve an extended measurement depth with the assistance of a graded index (Grin) lens. It relies on a highly stable broadband SLD light source, balanced detection techniques [21] , and differential delay lines [22] to achieve lower sensitivity and a wider dynamic range. These features make it more suitable for testing bonding interfaces in slab crystals.…”

High-Order Interference Effect Introduced by Polarization Mode Coupling in Polarization—Maintaining Fiber and Its Identification

“…Secondly, the dispersion of fiber-based WLI is compensated by inserting a segment of dispersion-shifted fiber (DSF) into one arm of MZI. Thirdly, we utilize the differential scanning MZI with two lenses to suppress the optical power fluctuation [ 17 ]. As shown in Figure 1 , a PMF with multiple perturbation points (denoted by point , , …, ) is tested by WLI.…”