Package of hollow micro-bottle resonator and refractive index sensing properties
-
摘要:
为提高传感器的稳定性和便携性，提出一种基于空心微瓶谐振腔的折射率传感器，对系统进行封装并对其折射率传感特性进行研究。仿真分析不同壁厚下空心微瓶谐振腔径向回音壁模式的光场分布，光场在微瓶内部的占比随着器件壁厚的减少而增加，有利于提高传感灵敏度。为减小空心微瓶谐振腔的壁厚，利用氢氟酸对石英毛细管进行腐蚀，使用光纤熔接机制备了薄壁空心微瓶谐振腔。采用紫外胶将耦合系统封装固定在载玻片上，器件稳定性和便携性得到提升。研究了封装器件在不同折射率匹配液下的传感特性，器件传感灵敏度为26.50 nm/RIU。该传感器具有稳定性强、灵活性高、损耗小等优点，在光微流控折射率检测方面拥有很大的应用潜力。
Abstract:To improve the stability and portability of the sensor, a refractive index sensor based on hollow micro-bottle resonator was proposed to package the system and study its refractive index sensing properties. The optical field distribution of radial echo-wall mode of hollow micro-bottle resonator under different wall thicknesses was simulated and analyzed. The proportion of the optical field inside the micro-bottle increased with the decrease of wall thickness of device, which was beneficial to improve the sensing sensitivity. To reduce the wall thickness, the quartz capillary was etched by hydrofluoric acid, which was used to fabricate the thin-wall hollow micro-bottle resonator by fusion splicer. The coupling system was packaged and fixed on a slide by using UV adhesive, which enhanced the stability and portability of the sensor. Finally, the sensing characteristics of the packaged device under different refractive index matching fluids were studied and the sensing sensitivity was 26.50 nm/RIU. The proposed sensor has the advantages of high stability, high flexibility and low loss, which has great application potential in optofluidic refractive index detection.
-
引言
凸透镜焦距的测量是大学《应用光学》课程中必做的实验之一，测量方法有：物距像距法、自准直法、光电法、平行光管法[1-6]。采用前3种方法测量薄凸透镜焦距时，光路比较简单，易于操作，学生容易掌握和理解。但这些方法中都需要用透镜的位置、成清晰像的位置、物的位置等参量，经运算得到透镜的焦距。此外，物距像距法和自准直法所得结果的准确度还受到人眼主观观察判断能力及像差的限制；光电法虽然能解决由像距的景深所引入的系统误差，但其测量精度还与透镜光心是否与支杆中心处于同一垂直于导轨平面有关，因此测量精度都偏低[7-10]。为了提高凸透镜焦距的测量精度，丰富透镜焦距的测量手段，可采用平行光管法测量透镜的焦距[11]。
1 基于平行光管法的薄凸透镜焦距测量原理
平行光管是一种能发射平行光束的精密的光学仪器，它有一个质量优良的准直物镜L0，其焦距是经过精确测定的[12-14]。本实验中所用的平行光管，其物镜焦距为143 mm(数值由厂家提供)。其焦距仪光学系统主要结构如图 1所示。
由图 1可以看出，测量透镜焦距时，平行光管以白炽灯作为光源，用滤光片来收窄光源参与成像光谱，用毛玻璃将不均匀的面光源转换成均匀的面光源照射到玻罗板上。玻罗板置于物镜的物方焦平面上，其上刻有5对平行线，如图 2所示。每对平行线中心的线距分别是20、10、4、2、1(单位：mm)。因此，从物镜发出的光为平行光束。平行光束经待测透镜后成清晰像于目镜的分划板上，只需测出玻罗板线对的像高，即可算出待测透镜的焦距。
![]()
图 2 玻罗板的平行线及线距标称值Figure 2. Porro board's parallel lines and nominal values of its interval本实验利用物像之间的比例关系测量透镜的焦距。用平行光管法测量凸透镜焦距的光路图如图 3所示。由物点(物高为y)发出的光经平行光管物镜Lo后成为平行光，它与光轴夹角的正切为y/fo，该光束经待测透镜Lx后成像在其焦平面上，像高为y′。从图中的几何关系可以看出待测透镜的焦距f′x为
![]()
图 3 平行光管法测量凸透镜焦距的光路图Figure 3. Convex lens' focal length measurement optical path based on parallel tube method$$ f^{\prime}_{x}=-\frac{y^{\prime}}{y} \cdot f^{\prime}_o $$ (1) 式中：f′o为平行光管物镜的焦距，其数值已标在平行光管(标称值为143 mm)；y为玻罗板上某一线对的间距；y′为用测微目镜测得的同一线对像的间距，y′ < 0；f′x为待测凸透镜的焦距。
2 实验步骤
本实验中各元件的等高共轴调节极为重要，若共轴调节不准，在测微目镜中就可能观察不到玻罗板中某一线对的像。因此，等高共轴是整个实验的关键之处。等高共轴的调节要点如下：
1) 粗调。分别使透镜光轴、“物”的中心、像屏中心及测微目镜光轴基本在平行光管光轴上；
2) 共轴调节的“大像追小像”法。在光具座上依次放置“物”、透镜和像屏，使“物”到像屏的距离大于6倍焦距估值[15]。透镜沿光具座平移时像屏上会出现一大一小两次清晰的像。先记住屏上小像中心位置，再在屏上出现大像时，上下左右细调“物”或者对透镜做转动等调节，使大像的中心趋近原先的小像中心位置，称为“大像追小像”。再观察小像位置，再次使大像追小像。经过几轮调节使大小像中心重合，说明“物”的中心已经与透镜共轴。
先旋转调节目镜，看清叉丝，然后仔细调节透镜与测微目镜间距，使玻罗板线对的像与叉丝基本消视差，再用小力偶矩轻轻地单向旋转测微目镜的鼓轮，使叉丝依次对准玻罗板线对的两条线中心，分别记下测微目镜的读数值y′1和y′2，y′=-|y′1-y′2 |，计算出焦距f′x=-f′o y′/y。
3 凸透镜焦距测量实验及精度分析
为验证本文方法测量凸透镜焦距的可行性，在WZG型多功能积木式组合光谱仪光学实验平台上，使用搭建的焦距仪光学系统(图 4)来测量待测透镜焦距。其中，图 5(a)为平行光管；图 5(b)为待测透镜，其焦距标称值为100 mm；图 5(c)为测微目镜，其倍率为15倍。
用平行光管法测量待测凸透镜的焦距，测量次数为6次，实际测量结果如表 1所示，其中选取玻罗板线对间距y=4 mm，f′o=143 mm，y′1、y′2分别为刻线对两条刻线在测微目镜中对应的读数。对6次待测透镜焦距值取平均值，求得待测透镜焦距的平均值f′x=99.862 mm。实验结果可以看出，采用平行光管法可以测量薄凸透镜的焦距。
表 1 平行光管法测量的数据记录mm Table 1. Data records of parallel tube method measurements次数 1 2 3 4 5 6 y′1 2.280 2.220 2.240 2.210 2.280 2.230 y′2 5.050 5.020 5.040 5.020 5.050 5.040 y′=-|y′1-y′2| -2.770 -2.800 -2.800 -2.810 -2.770 -2.810 $f_{x}^{\prime}=-\frac{y^{\prime}}{y} \cdot f_{o}^{\prime} $ 99.028 100.100 100.100 100.458 99.028 100.458 为验证平行光管法测量凸透镜焦距的精确性，将其与物距像距法、自准直法、光电法相比，以同一待测透镜为研究对象，其中，a)物距像距法：f′x=98.650 mm；b)自准直法：f′x=101.452 mm；c)光电法：100.190 mm；d)平行光管法：f′x=99.862 mm。通过数据可以看出，采用平行光管法测得焦距的相对误差最小，仅为0.138%。结果表明，平行光管法可以高精度地测量薄凸透镜的焦距。
采用平行光管法测量凸透镜焦距时，测量结果的不确定度分量有：1)测y′的测微目镜的仪器误差限；2)平行光管物镜焦距的不确定度；3)玻罗板线对间距的误差影响，可忽略不计。
4 结论
针对薄凸透镜焦距的测量，结合平行光管法的有关理论，提出了用平行光管法测量薄凸透镜焦距。该方法在一定程度上提高了薄凸透镜焦距测量的测量精度，并通过实验验证了该方法的可行性、有效性、精确性，对透镜焦距测量的研究及应用具有一定的实际意义。
-
![]()
图 1 空心微瓶谐振腔与光纤融锥耦合示意图与空心微瓶谐振腔的横截面示意图
Figure 1. Schematic diagram of hollow micro-bottle resonator coupled with tapered fiber and cross section of micro-bottle structure
![]()
图 2 不同壁厚下空心微瓶谐振腔的光场分布
Figure 2. Optical field distribution of hollow micro-bottle resonator with different wall thicknesses
![]()
图 3 石英毛细管的腐蚀实验装置和腐蚀前后横截面示意图
Figure 3. Schematic of corrosion experimental device and cross section of quartz capillary before and after corrosion
![]()
图 6 封装前后空心微瓶谐振腔的传输谱以及稳定性测试
Figure 6. Transmission spectra of hollow micro-bottle resonator before and after package and stability test
![]()
图 7 折射率传感实验装置
Figure 7. Schematic diagram of refractive index sensing experimental device
![]()
图 8 空心微瓶谐振腔的传输谱及其谐振峰拟合
Figure 8. Transmission spectrum of hollow micro-bottle resonator and its resonance peak fitting
-
[1] 孙航, 刘笑尘, 王梓杰, 等. 毛细管内嵌微球谐振腔的温度传感特性研究[J]. 应用光学,2021,42(5):926-931. doi: 10.5768/JAO202142.0508001 SUN Hang, LIU Xiaochen, WANG Zijie, et al. Temperature sensing characteristics of a microsphere resonator embedded in a capillary[J]. Journal of Applied Optics,2021,42(5):926-931. doi: 10.5768/JAO202142.0508001
[2] 刘笑尘, 谢严, 陈溢琦, 等. 光纤耦合双微球谐振腔及其模式分裂特性[J]. 光学学报,2021,41(13):140-148. LIU Xiaochen, XIE Yan, CHEN Yiqi, et al. Fiber coupled double microsphere resonator and its mode splitting characteristics[J]. Acta Optica Sinica,2021,41(13):140-148.
[3] 张建辉, 徐鹏飞, 李小枫, 等. 高Q光学微球腔角速度传感效应验证[J]. 应用光学,2013,34(6):1057-1061. ZHANG Jianhui, XU Pengfei, LI Xiaofeng, et al. Validation of high-Q optical microsphere resonator angular velocity sensor[J]. Journal of Applied Optics,2013,34(6):1057-1061.
[4] 林春婷, 吴根柱, 汪成程, 等. 基于模式分裂现象的在纤式双微盘谐振腔[J]. 光学学报,2021,41(4):76-81. LIN Chunting, WU Genzhu, WANG Chengcheng, et al. In-fiber double microdisk resonator based on mode splitting[J]. Acta Optica Sinica,2021,41(4):76-81.
[5] JIANG Xuefeng, XIAO Yunfeng, YANG Qifan, et al. Free-space coupled, ultralow-threshold Raman lasing from a silica microcavity[J]. Applied Physics Letters,2013,103(10):101102. doi: 10.1063/1.4820133
[6] 韩毅帅, 孙天玉, 贾慧民, 等. 氮化铝微环谐振腔临界耦合条件及制备工艺研究[J]. 光子学报,2021,50(5):94-102. HAN Yishuai, SUN Tianyu, JIA Huimin, et al. Critical coupling condition and preparation technology of aluminum nitride microring resonator[J]. Acta Photonica Sinica,2021,50(5):94-102.
[7] 陈伟. 聚合物材料并联双环型温度传感器的设计[J]. 应用光学,2010,31(3):495-498. doi: 10.3969/j.issn.1002-2082.2010.03.032 CHEN Wei. Design of polymer parallel double-ring temperature sensor[J]. Journal of Applied Optics,2010,31(3):495-498. doi: 10.3969/j.issn.1002-2082.2010.03.032
[8] ZHANG Yanan, ZHU Naisi, GAO Peng, et al. Magnetic field sensor based on ring WGM resonator infiltrated with magnetic fluid[J]. Journal of Magnetism and Magnetic Materials,2020,493:165701. doi: 10.1016/j.jmmm.2019.165701
[9] MELDRUM A, MARSIGLIO F. Capillary-type microfluidic sensors based on optical whispering gallery mode resonances[J]. Reviews in Nanoscience and Nanotechnology,2014,3(3):193-209. doi: 10.1166/rnn.2014.1054
[10] 侯峰裕, 王梓杰, 余洋, 等. 空心微瓶谐振腔的曲率模型及其传输特性研究[J]. 应用光学,2020,41(5):1122-1128. doi: 10.5768/JAO202041.0508001 HOU Fengyu, WANG Zijie, YU Yang, et al. Research on curvature model and transmission characteristics of hollow micro-bottle resonator[J]. Journal of Applied Optics,2020,41(5):1122-1128. doi: 10.5768/JAO202041.0508001
[11] WANG Mengyu, YANG Yu, LU Zhizhou, et al. Experimental demonstration of nonlinear scattering processes in a microbottle resonator based on a robust packaged platform[J]. Journal of Lightwave Technology,2021,39(18):5917-5924. doi: 10.1109/JLT.2021.3092636
[12] SENTHIL MURUGAN G, PETROVICH M N, JUNG Y, et al. Hollow-bottle optical microresonators[J]. Optics Express,2011,19(21):20773-20784. doi: 10.1364/OE.19.020773
[13] YU Xiaochong, TANG Shuijing, LIU Wenjing, et al. Single-molecule optofluidic microsensor with interface whispering gallery modes[J]. Proceedings of the National Academy of Sciences of the United States of America,2022,119(6):e2108678119. doi: 10.1073/pnas.2108678119
[14] GUO Zhihe, LU Qijing, ZHU Chenggang, et al. Ultra-sensitive biomolecular detection by external referencing optofluidic microbubble resonators[J]. Optics Express,2019,27(9):12424-12435. doi: 10.1364/OE.27.012424
[15] WANG Zijie, ZHANG Xiaobei, ZHANG Qi, et al. Monitoring and identifying pendant droplets in microbottle resonators[J]. Photonics Research,2022,10(3):662-667. doi: 10.1364/PRJ.450535
[16] WARD J M, YANG Yong, LEI Fuchuan, et al. Nanoparticle sensing beyond evanescent field interaction with a quasi-droplet microcavity[J]. Optica,2018,5(6):674-677. doi: 10.1364/OPTICA.5.000674
[17] CHEN Zhenmin, GUO Zhihe, MU Xin, et al. Packaged microbubble resonator optofluidic flow rate sensor based on Bernoulli Effect[J]. Optics Express,2019,27(25):36932-36940. doi: 10.1364/OE.27.036932
[18] WANG Zijie, ZHANG Xiaobei, ZHAO Shuaichang, et al. High-sensitivity flow rate sensor enabled by higher order modes of packaged microbottle resonator[J]. IEEE Photonics Technology Letters,2021,33(12):599-602. doi: 10.1109/LPT.2021.3078487
[19] CAI M, PAINTER O, VAHALA K J. Observation of critical coupling in a fiber taper to a silica-microsphere whispering-gallery mode system[J]. Physical Review Letters,2000,85(1):74-77. doi: 10.1103/PhysRevLett.85.74
[20] 王鹏飞, 李昂震. 回音壁模式光学微腔器件的封装与集成[J]. 光子学报,2019,48(11):94-103. WANG Pengfei, LI Angzhen. Packaging and integration of whispering gallery modes optical microcavity devices[J]. Acta Photonica Sinica,2019,48(11):94-103.
[21] YAN Yingzhan, ZOU Changling, YAN Shubin, et al. Robust spot-packaged microsphere-taper coupling structure for in-line optical sensors[J]. IEEE Photonics Technology Letters,2011,23(22):1736-1738. doi: 10.1109/LPT.2011.2169051
[22] WANG Pengfei, DING Ming, LEE T, et al. Packaged chalcogenide microsphere resonator with high Q-factor[J]. Applied Physics Letters,2013,102(13):131110. doi: 10.1063/1.4801474
[23] DONG Yongchao, WANG Keyi, JIN Xueying. Packaged microsphere-taper coupling system with a high Q factor[J]. Applied Optics,2015,54(2):277-284. doi: 10.1364/AO.54.000277
[24] TANG Ting, WU Xiang, LIU Liying, et al. Packaged optofluidic microbubble resonators for optical sensing[J]. Applied Optics,2016,55(2):395-399. doi: 10.1364/AO.55.000395
[25] YANG Daquan, DUAN Bing, WANG Aiqiang, et al. Packaged microbubble resonator for versatile optical sensing[J]. Journal of Lightwave Technology,2020,38(16):4555-4559. doi: 10.1109/JLT.2020.2988206
[26] WHITE I M, FAN Xudong. On the performance quantification of resonant refractive index sensors[J]. Optics Express,2008,16(2):1020-1028. doi: 10.1364/OE.16.001020
-
期刊类型引用(4)
1. 刘坤，李克武，王爽，王志斌，张易琨. 弹光调制器动态参数测量与高效驱动匹配研究. 应用光学. 2024(02): 415-421 . 
本站查看
2. 杨军营，韩培高，魏莹莹. 无频响影响的光弹调制器定标新方法. 中国激光. 2024(08): 127-133 . 百度学术
3. 刘坤，李克武，李坤钰，王爽，王志斌. 弹光调制器相频特性分析与稳定控制技术. 激光杂志. 2024(07): 36-41 . 百度学术
4. 臧晓阳，李克武，王志斌，李坤钰，梁振坤，刘坤. 快轴可调弹光调制器闭环稳定控制研究. 激光与光电子学进展. 2023(07): 329-336 . 百度学术
其他类型引用(4)
下载:
计量
- 文章访问数: 500
- HTML全文浏览量: 161
- PDF下载量: 62
- 被引次数: 8
陕公网安备 61011302001501号 