Ptical Feedback Interferometry News Today

The mechanical properties of materials hold significant importance in fundamental research, material, mechanical and civil engineering. These properties are often characterized by some elastic parameters, e.g., Young's modulus, shear modulus and Poisson's ratio. Self-mixing interferometry (SMI) is a unique non-destructive sensing technology that requires minimal components. In this work, we have developed a time-multiplexed fiber-coupled laser SMI sensor in conjunction with impulse exc...

Laser optical feedback interferometry (OFI) is a unique one-channel interferometric measurement technology with the advantages of compact structure, low implementation cost and easy alignment. However, it has a critical challenge that the visibility of interference fringe is often low and further induces low measurement sensitivity, especially in occasions when the optical feedback strength is feeble, e.g., biomedical and fluid detection. Recently, it has been demonstrated that period-one (P1) d...

Self-mixing interferometry (SMI) is a promising sensing technology. As well as its compact structure, self-alignment and low implementation cost, it has an important advantage that conventional two-beam interferometry does not have, i.e., SMI signal fringe evolves into asymmetrical shape with increasing optical feedback level, which leads to discrimination of target movement directions for unambiguous displacement measurement possible by a single-channel interferometric signal. It is usually ach...