Field Evaluation of a Portable Whispering Gallery Mode Accelerometer
An accelerometer utilising the optomechanical coupling between an optical whispering gallery mode (WGM) resonance and the motion of the WGM cavity itself was prototyped and field-tested on a vehicle. We describe the assembly of this portable, battery operated sensor and the field-programmable gate a...
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| Format: | Article |
| Language: | English |
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MDPI AG
2018-11-01
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| Series: | Sensors |
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| Online Access: | https://www.mdpi.com/1424-8220/18/12/4184 |
| _version_ | 1818001842846564352 |
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| author | Ying Lia Li P. F. Barker |
| author_facet | Ying Lia Li P. F. Barker |
| author_sort | Ying Lia Li |
| collection | DOAJ |
| description | An accelerometer utilising the optomechanical coupling between an optical whispering gallery mode (WGM) resonance and the motion of the WGM cavity itself was prototyped and field-tested on a vehicle. We describe the assembly of this portable, battery operated sensor and the field-programmable gate array automation. Pre-trial testing using an electrodynamic shaker demonstrated linear scale-factors with <0.3% standard deviation (<inline-formula> <math display="inline"> <semantics> <mrow> <mo>±</mo> <mn>6</mn> </mrow> </semantics> </math> </inline-formula> g range where g = 9.81 ms<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula>), and a strong normalised cross-correlation coefficient (NCCC) of r<inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mrow></mrow> <mrow> <mi>ICP</mi> <mo>/</mo> <mi>WGM</mi> </mrow> </msub> <mo>=</mo> <mn>0.997</mn> </mrow> </semantics> </math> </inline-formula> when compared with an integrated circuit piezoelectric (ICP) accelerometer. A noise density of 40 <inline-formula> <math display="inline"> <semantics> <mi mathvariant="sans-serif">μ</mi> </semantics> </math> </inline-formula>g Hz<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> was obtained for frequencies of 2⁻7 kHz, increasing to 130 <inline-formula> <math display="inline"> <semantics> <mi mathvariant="sans-serif">μ</mi> </semantics> </math> </inline-formula>g Hz<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> at 200 Hz, and 250 <inline-formula> <math display="inline"> <semantics> <mi mathvariant="sans-serif">μ</mi> </semantics> </math> </inline-formula>g Hz<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> at 100 Hz. A reduction in the cross-correlation was found during the trial, r<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mrow> <mi>ICP</mi> <mo>/</mo> <mi>WGM</mi> </mrow> </msub> </semantics> </math> </inline-formula> = 0.36, which we attribute to thermal fluctuations, mounting differences, and the noisy vehicle environment. The deployment of this hand-fabricated sensor, shown to operate and survive during ±60 g shocks, demonstrates important steps towards the development of a chip-scale device. |
| first_indexed | 2024-04-14T03:39:23Z |
| format | Article |
| id | doaj.art-477220e3cedb486ca23bc1d3c3715ef6 |
| institution | Directory Open Access Journal |
| issn | 1424-8220 |
| language | English |
| last_indexed | 2024-04-14T03:39:23Z |
| publishDate | 2018-11-01 |
| publisher | MDPI AG |
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| series | Sensors |
| spelling | doaj.art-477220e3cedb486ca23bc1d3c3715ef62022-12-22T02:14:36ZengMDPI AGSensors1424-82202018-11-011812418410.3390/s18124184s18124184Field Evaluation of a Portable Whispering Gallery Mode AccelerometerYing Lia Li0P. F. Barker1Department of Physics & Astronomy, University College London, London WC1E 6BT, UKDepartment of Physics & Astronomy, University College London, London WC1E 6BT, UKAn accelerometer utilising the optomechanical coupling between an optical whispering gallery mode (WGM) resonance and the motion of the WGM cavity itself was prototyped and field-tested on a vehicle. We describe the assembly of this portable, battery operated sensor and the field-programmable gate array automation. Pre-trial testing using an electrodynamic shaker demonstrated linear scale-factors with <0.3% standard deviation (<inline-formula> <math display="inline"> <semantics> <mrow> <mo>±</mo> <mn>6</mn> </mrow> </semantics> </math> </inline-formula> g range where g = 9.81 ms<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula>), and a strong normalised cross-correlation coefficient (NCCC) of r<inline-formula> <math display="inline"> <semantics> <mrow> <msub> <mrow></mrow> <mrow> <mi>ICP</mi> <mo>/</mo> <mi>WGM</mi> </mrow> </msub> <mo>=</mo> <mn>0.997</mn> </mrow> </semantics> </math> </inline-formula> when compared with an integrated circuit piezoelectric (ICP) accelerometer. A noise density of 40 <inline-formula> <math display="inline"> <semantics> <mi mathvariant="sans-serif">μ</mi> </semantics> </math> </inline-formula>g Hz<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> was obtained for frequencies of 2⁻7 kHz, increasing to 130 <inline-formula> <math display="inline"> <semantics> <mi mathvariant="sans-serif">μ</mi> </semantics> </math> </inline-formula>g Hz<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> at 200 Hz, and 250 <inline-formula> <math display="inline"> <semantics> <mi mathvariant="sans-serif">μ</mi> </semantics> </math> </inline-formula>g Hz<inline-formula> <math display="inline"> <semantics> <msup> <mrow></mrow> <mrow> <mo>−</mo> <mn>1</mn> <mo>/</mo> <mn>2</mn> </mrow> </msup> </semantics> </math> </inline-formula> at 100 Hz. A reduction in the cross-correlation was found during the trial, r<inline-formula> <math display="inline"> <semantics> <msub> <mrow></mrow> <mrow> <mi>ICP</mi> <mo>/</mo> <mi>WGM</mi> </mrow> </msub> </semantics> </math> </inline-formula> = 0.36, which we attribute to thermal fluctuations, mounting differences, and the noisy vehicle environment. The deployment of this hand-fabricated sensor, shown to operate and survive during ±60 g shocks, demonstrates important steps towards the development of a chip-scale device.https://www.mdpi.com/1424-8220/18/12/4184accelerometerprototypewhispering gallery modeoptomechanicsoptical sensingcavityoptical sensorsresonatorfield trial |
| spellingShingle | Ying Lia Li P. F. Barker Field Evaluation of a Portable Whispering Gallery Mode Accelerometer Sensors accelerometer prototype whispering gallery mode optomechanics optical sensing cavity optical sensors resonator field trial |
| title | Field Evaluation of a Portable Whispering Gallery Mode Accelerometer |
| title_full | Field Evaluation of a Portable Whispering Gallery Mode Accelerometer |
| title_fullStr | Field Evaluation of a Portable Whispering Gallery Mode Accelerometer |
| title_full_unstemmed | Field Evaluation of a Portable Whispering Gallery Mode Accelerometer |
| title_short | Field Evaluation of a Portable Whispering Gallery Mode Accelerometer |
| title_sort | field evaluation of a portable whispering gallery mode accelerometer |
| topic | accelerometer prototype whispering gallery mode optomechanics optical sensing cavity optical sensors resonator field trial |
| url | https://www.mdpi.com/1424-8220/18/12/4184 |
| work_keys_str_mv | AT yingliali fieldevaluationofaportablewhisperinggallerymodeaccelerometer AT pfbarker fieldevaluationofaportablewhisperinggallerymodeaccelerometer |