High Sensitivity and Full-circle Optical Rotary Sensor for Non-cooperatively Tracing Wrist Tremor with Nanoradian Resolution

<div> An optical rotary sensor based on laser self-mixing interferometry is proposed, which enables noncontact and full-circle rotation measurement of non-cooperative targets with high resolution and sensitivity. The prototype demonstrates that the resolution is 0.1μrad and the linearity is 2.33×10-4. Stability of the prototype is 2μrad over 3600s and the repeatability error is below 0.84°under 9-gruop full-circle tests. The theoretical resolution reaches up to 16nrad. Random rotation has been successfully traced with a bionic hand to simulate the tremor process. Error analysis and limitation discussion have been also carried out in the paper. Although the accuracy needs further improvement compared with the best rotary sensor, this method has its unique advantages of non-cooperative target sensing, high sensitivity and electromagnetic immunity. Hence, the optical rotary sensor provides a promising alternative in precise rotation measurement, tremor tracing and nano-motion monitoring. </div>

Download Full-text

High Sensitivity and Full-circle Optical Rotary Sensor for Non-cooperatively Tracing Wrist Tremor with Nanoradian Resolution

10.36227/techrxiv.14686071.v1 ◽

2021 ◽

Author(s):

Xin Xu ◽

Zongren Dai ◽

Yifang Wang ◽

Mingfang Li ◽

Yidong Tan

Keyword(s):

High Resolution ◽

Error Analysis ◽

High Sensitivity ◽

Promising Alternative ◽

Rotation Measurement ◽

Full Circle ◽

Repeatability Error ◽

Process Error ◽

Circle Rotation ◽

Electromagnetic Immunity

<div> An optical rotary sensor based on laser self-mixing interferometry is proposed, which enables noncontact and full-circle rotation measurement of non-cooperative targets with high resolution and sensitivity. The prototype demonstrates that the resolution is 0.1μrad and the linearity is 2.33×10-4. Stability of the prototype is 2μrad over 3600s and the repeatability error is below 0.84°under 9-gruop full-circle tests. The theoretical resolution reaches up to 16nrad. Random rotation has been successfully traced with a bionic hand to simulate the tremor process. Error analysis and limitation discussion have been also carried out in the paper. Although the accuracy needs further improvement compared with the best rotary sensor, this method has its unique advantages of non-cooperative target sensing, high sensitivity and electromagnetic immunity. Hence, the optical rotary sensor provides a promising alternative in precise rotation measurement, tremor tracing and nano-motion monitoring. </div>

Download Full-text

High Sensitivity and Full-circle Optical Rotary Sensor for Non-cooperatively Tracing Wrist Tremor with Nanoradian Resolution

10.36227/techrxiv.14686071.v3 ◽

2021 ◽

Author(s):

Xin Xu ◽

Zongren Dai ◽

Yifan Wang ◽

Mingfang Li ◽

Yidong Tan

Keyword(s):

High Resolution ◽

Error Analysis ◽

High Sensitivity ◽

Promising Alternative ◽

Rotation Measurement ◽

Full Circle ◽

Repeatability Error ◽

Circle Rotation ◽

Electromagnetic Immunity

<div> In this paper, a novel optical rotary sensor based on laser self-mixing interferometry is developed for the full-circle rotation measurement. The proposed sensor is convenient to use for it does not need any contact with the target or a cooperative mirror. A prototype is fabricated and tested. The measured results demonstrate a good performance compared with other optical rotary sensors, in terms of the 0.1 μrad resolution, the 2.33×10-4 linearity and 2 μrad stability over one hour. Additionally, the repeatability error is below 14.66 mrad under 9-group full-circle tests, which exhibits the potential to be instrumentalized reliably. Error analysis and limitation discussion have been also carried out. Although the accuracy needs further improvement compared with the best rotary sensor, this method has its unique advantages of high resolution, non-cooperative target sensing and electromagnetic immunity. Hence, the proposed optical rotary sensor provides a promising alternative in precise rotation measurement, tremor tracing and nano-motion monitoring.</div>In this paper, a novel optical rotary sensor based on laser self-mixing interferometry is developed for the full-circle rotation measurement. The proposed sensor is convenient to use for it does not need any contact with the target or a cooperative mirror. A prototype is fabricated and tested. The measured results demonstrate a good performance compared with other optical rotary sensors, in terms of the 0.1 μrad resolution, the 2.33×10-4 linearity and 2 μrad stability over one hour. Additionally, the repeatability error is below 14.66 mrad under 9-group full-circle tests, which exhibits the potential to be instrumentalized reliably. Error analysis and limitation discussion have been also carried out. Although the accuracy needs further improvement compared with the best rotary sensor, this method has its unique advantages of high resolution, non-cooperative target sensing and electromagnetic immunity. Hence, the proposed optical rotary sensor provides a promising alternative in precise rotation measurement, tremor tracing and nano-motion monitoring.

Download Full-text

Backscattered Electron Imaging of GaAs/AlGaAs Super Lattice Structures with an Ultra-High- Resolution SEM

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100103103 ◽

1988 ◽

Vol 46 ◽

pp. 204-205

Author(s):

Kazumichi Ogura ◽

Michael M. Kersker

Keyword(s):

High Resolution ◽

Layer Structure ◽

High Sensitivity ◽

Beam Current ◽

Electron Beam Current ◽

Lattice Structures ◽

Super Lattice ◽

Different Types ◽

Backscattered Electron ◽

Electron Imaging

Backscattered electron (BE) images of GaAs/AlGaAs super lattice structures were observed with an ultra high resolution (UHR) SEM JSM-890 with an ultra high sensitivity BE detector. Three different types of super lattice structures of GaAs/AlGaAs were examined. Each GaAs/AlGaAs wafer was cleaved by a razor after it was heated for approximately 1 minute and its crosssectional plane was observed.First, a multi-layer structure of GaAs (100nm)/AlGaAs (lOOnm) where A1 content was successively changed from 0.4 to 0.03 was observed. Figures 1 (a) and (b) are BE images taken at an accelerating voltage of 15kV with an electron beam current of 20pA. Figure 1 (c) is a sketch of this multi-layer structure corresponding to the BE images. The various layers are clearly observed. The differences in A1 content between A1 0.35 Ga 0.65 As, A1 0.4 Ga 0.6 As, and A1 0.31 Ga 0.69 As were clearly observed in the contrast of the BE image.

Download Full-text

Design of a high sensitivity and low power ultrasound receiver with a high-resolution SAR ADC for photoacoustic sensing and imaging

10.32657/10356/144400 ◽

2020 ◽

Author(s):

◽

Chuanshi Yang

Keyword(s):

High Resolution ◽

Low Power ◽

High Sensitivity ◽

Sar Adc ◽

Power Ultrasound

Download Full-text

High-Resolution and High-Sensitivity Flexible Capacitive Pressure Sensors Enhanced by a Transferable Electrode Array and a Micropillar–PVDF Film

ACS Applied Materials & Interfaces ◽

10.1021/acsami.0c23042 ◽

2021 ◽

Vol 13 (6) ◽

pp. 7635-7649

Author(s):

Zebang Luo ◽

Jing Chen ◽

Zhengfang Zhu ◽

Lin Li ◽

Yi Su ◽

...

Keyword(s):

High Resolution ◽

Pressure Sensors ◽

Electrode Array ◽

High Sensitivity ◽

Pvdf Film

Download Full-text

Hybrid Grating in Reduced-Diameter Fiber for Temperature-Calibrated High-Sensitivity Refractive Index Sensing

Applied Sciences ◽

10.3390/app9091923 ◽

2019 ◽

Vol 9 (9) ◽

pp. 1923

Author(s):

Biqiang Jiang ◽

Zhen Hao ◽

Dingyi Feng ◽

Kaiming Zhou ◽

Lin Zhang ◽

...

Keyword(s):

Refractive Index ◽

Simultaneous Measurement ◽

Surrounding Medium ◽

High Sensitivity ◽

Fiber Grating ◽

Bragg Resonance ◽

Core Mode ◽

Promising Alternative ◽

Sensing Applications ◽

Highly Sensitive

We propose and experimentally demonstrate a hybrid grating, in which an excessively tilted fiber grating (Ex-TFG) and a fiber Bragg grating (FBG) were co-inscribed in a reduced-diameter fiber (RDF). The hybrid grating showed strong resonances due to coupling among core mode and a set of polarization-dependent cladding modes. This coupling showed enhanced evanescent fields by the reduced cladding size, thus allowing stronger interaction with the surrounding medium. Moreover, the FBG’s Bragg resonance confined by the thick cladding was exempt from the change of the surrounding medium’s refractive index (RI), and then the FBG can work as a temperature compensator. As a result, the Ex-TFG in RDF promised a highly sensitive RI measurement, with a sensitivity up to ~1224 nm/RIU near the RI of 1.38. Through simultaneous measurement of temperature and RI, the temperature dependence of water’s RI is then determined. Therefore, the proposed hybrid grating with a spectrum of multi-peaks embedded with a sharp Bragg resonance is a promising alternative for the simultaneous measurement of multi-parameters for many RI-based sensing applications.

Download Full-text