[1] K. A. Willets and R. P. Van Duyne, “Localized surface plasmon resonance spectroscopy and sensing,” Annual Review of Physical Chemistry, 2007, 58: 267–297.

[2] P. A. Martin, “Near-infrared diode laser spectroscopy in chemical process and environmental air monitoring,” Chemical Society Reviews, 2002, 31(4): 201–210.

[3] R. A. Halvorson and P. J. Vikesland, “Surface-enhanced Raman spectroscopy (SERS) for environmental analyses,” Environmental Science & Technology, 2010, 44(20): 7749–7755.

[4] C. Kulesa, “Terahertz spectroscopy for astronomy: From comets to cosmology,” IEEE Transactions on Terahertz Science and Technology, 2011, 1(1): 232–240.

[5] F. Hoyle, N. Wickramasinghe, S. Al-Mufti, A. Olavesen, and D. Wickramasinghe, “Infrared spectroscopy over the 2.9–3.9 μm waveband in biochemistry and astronomy,” in Astronomical Origins of Life, Springer, 2000, pp. 161–166,

[6] L. P. Choo-Smith, H. Edwards, H. P. Endtz, J. Kros, F. Heule, H. Barr, et al., “Medical applications of Raman spectroscopy: from proof of principle to clinical implementation,” Biopolymers: Original Research on Biomolecules, 2002, 67(1): 1–9.

[7] A. Sakudo, “Near-infrared spectroscopy for medical applications: current status and future perspectives,” Clinica Chimica Acta, 2016, 455: 181–188.

[8] T. Matsumoto, S. Fujita, and T. Baba, “Wavelength demultiplexer consisting of photonic crystal superprism and superlens,” Optics Express, 2005, 13(26): 10768–10776.

[9] A. T. U. R. O. AP2041B. Available at http://www.apext.com/pdf/optical-spectrum-analyzer .pdf.

[10] Y. O. AQ6370D. Available at https://www.yokogawa.com/pdf.

[11] P. R. Griffiths and J. A. De Haseth, “Fourier transform infrared spectrometry,” New Jersey: John Wiley & Sons, 2007: 171.

[12] D. M. Kita, B. Miranda, D. Favela, D. Bono, J. Michon, H. Lin, et al., “High-performance and scalable on-chip digital Fourier transform spectroscopy,” Nature Communications, 2018, 9(1): 1–7.

[13] M. C. Souza, A. Grieco, N. C. Frateschi, and Y. Fainman, “Fourier transform spectrometer on silicon with thermo-optic non-linearity and dispersion correction,” Nature Communications, 2018, 9(1): 1–8.

[14] Q. Cheng, F. Duan, T. Huang, and J. Wang, “Forward fiber Fourier transform spectrometer modeling and design with PZT phase modulation real-time compensation,” Applied Optics, 2018, 57(18): 5025–5035.

[15] M. Chakrabarti, M. L. Jakobsen, and S. G. Hanson, “Speckle-based spectrometer,” Optics Letters, 2015, 40(14): 3264–3267.

[16] N. K. Metzger, R. Spesyvtsev, G. D. Bruce, B. Miller, G. T. Maker, G. Malcolm, et al., “Harnessing speckle for a sub-femtometre resolved broadband wavemeter and laser stabilization,” Nature Communications, 2017, 8: 15610.

[17] B. Redding and H. Cao, “Using a multimode fiber as a high-resolution, low-loss spectrometer,” Optics Letters, 2012, 37(16): 3384–3386.

[18] -. K. -etinda-, M. F. Toy, O. Ferhano-lu, and F. -ivitci, “A speckle-enhanced prism spectrometer with high dynamic range,” IEEE Photonics Technology Letters, 2018, 30(24): 2139–2142.

[19] S. K. -etinda-, M. F. Toy, O. Ferhano-lu, and F. Civitci, “Scattering metal waveguide based speckle-enhanced prism spectrometry,” Journal of Lightwave Technology, 2020, 38(7): 2022–2027.

[20] N. H. Wan, F. Meng, T. Schr-der, R.-J. Shiue, E. H. Chen, and D. Englund, “High-resolution optical spectroscopy using multimode interference in a compact tapered fibre,” Nature Communications, 2015, 6(1): 1–6.

[21] A. Shamsoddini and J. C. Trinder, “Image texture preservation in speckle noise suppression,” ISPRS TC VII Symposium – 100 Years ISPRS, 2010, 7: 239–244.

[22] W. S. Ha, S. J. Lee, K. H. Oh, Y. M. Jung, and J. K. Kim, “Speckle reduction in near-field image of multimode fiber with a piezoelectric transducer,” Journal of the Optical Society of Korea, 2008, 12(3): 126–130.

[23] E. Fujiwara, M. F. M. dos Santos, and C. K. Suzuki, “Optical fiber specklegram sensor analysis by speckle pattern division,” Applied Optics, 2017, 56(6): 1585–1590.

[24] E. Fujiwara, L. E. da Silva, T. H. Marques, and C. M. Cordeiro, “Polymer optical fiber specklegram strain sensor with extended dynamic range,” Optical Engineering, 2018, 57(11): 116107.

[25] P. Wu, S. Zhu, M. Hong, F. Chen, and H. Liu, “Specklegram temperature sensor based on femtosecond laser inscribed depressed cladding waveguides in Nd: YAG crystal,” Optics & Laser Technology, 2019, 113: 11–14.

[26] Y. Liu, Q. Qin, H. H. Liu, Z. W. Tan, and M. G. Wang, “Investigation of an image processing method of step-index multimode fiber specklegram and its application on lateral displacement sensing,” Optical Fiber Technology, 2018, 46: 48–53.

[27] H. Cao, “Perspective on speckle spectrometers,” Journal of Optics, 2017, 19: 060402.

[28] B. Redding, S. F. Liew, R. Sarma, and H. Cao, “Compact spectrometer based on a disordered photonic chip,” Nature Photonics, 2013, 7(9): 746–751.

[29] P. Gysel and R. K. Staubli, “Statistical properties of Rayleigh backscattering in single-mode fibers,” Journal of Lightwave Technology, 1990, 8(4): 561–567.

[30] P. Healey, “Fading in heterodyne OTDR,” Electronics Letters, 1984, 20(1): 30–32.

[31] K. Shimizu, T. Horiguchi, and Y. Koyamada, “Characteristics and reduction of coherent fading noise in Rayleigh backscattering measurement for optical fibers and components,” Journal of Lightwave Technology, 1992, 10(7): 982–987.

[32] J. Zhou, Z. Pan, Q. Ye, H. Cai, R. Qu, and Z. Fang, “Characteristics and explanations of interference fading of a phi-OTDR with a multi-frequency source,” Journal of Lightwave Technology, 2013, 31(17): 2947–2954.

[33] B. Redding, S. M. Popoff, and H. Cao, “All-fiber spectrometer based on speckle pattern reconstruction,” Optics Express, 2013, 21(5): 6584–6600.

[34] S. G. Hanson, M. L. Jakobsen, and M. Chakrabarti, “The dynamic speckle-based wavemeter,” in SPECKLE 2018: VII International Conference on Speckle Metrology, Poland, 2018, pp: 10834: 108342D.

[35] L. ODonnell, K. Dholakia, and G. D. Bruce, “High speed determination of laser wavelength using Poincaré descriptors of speckle,” Optics Communications, 2020, 459: 124906.

[36] A. Dávila and J. Rayas, “Single-shot phase detection in a speckle wavemeter for the measurement of femtometric wavelength change,” Optics and Lasers in Engineering, 2020, 125: 105856.

[37] Y. Kwak, S. M. Park, Z. Ku, A. Urbas, and Y. L. Kim, “A pearl spectrometer,” Nano Letters, 2021, 21(2): 921–930.

[38] K. Monakhova, K. Yanny, N. Aggarwal, and L. Waller, “Spectral diffusercam: lensless snapshot hyperspectral imaging with a spectral filter array,” Optica, 2020, 7(10): 1298–1307.

[39] E. Huang, Q. Ma, and Z. Liu, “Etalon array reconstructive spectrometry,” Scientific Reports, 2017, 7(1): 1–6.

[40] J. Bao and M. G. Bawendi, “A colloidal quantum dot spectrometer,” Nature, 2015, 523(7558): 67–70.

[41] Z. Yang, T. Albrow-Owen, H. Cui, J. Alexander-Webber, F. Gu, X. Wang, et al., “Single-nanowire spectrometers,” Science, 2019, 365(6457): 1017–1020.

[42] X. Gan, N. Pervez, I. Kymissis, F. Hatami, and D. Englund, “A high-resolution spectrometer based on a compact planar two-dimensional photonic crystal cavity array,” Applied Physics Letters, 2012, 100(23): 231104.

[43] Z. Wang, S. Yi, A. Chen, M. Zhou, T. S. Luk, A. James, et al., “Single-shot on-chip spectral sensors based on photonic crystal slabs,” Nature Communications, 2019, 10(1): 1–6.

[44] C. Kim, W. B. Lee, S. K. Lee, Y. T. Lee, and H. -N. Lee, “Fabrication of 2D thin-film filter-array for compressive sensing spectroscopy,” Optics and Lasers in Engineering, 2019, 115: 53–58.

[45] T. W. Kohlgraf-Owens and A. Dogariu, “Transmission matrices of random media: means for spectral polarimetric measurements,” Optics Letters, 2010, 35(13): 2236–2238.

[46] B. Redding, S. M. Popoff, Y. Bromberg, M. A. Choma, and H. Cao, “Noise analysis of spectrometers based on speckle pattern reconstruction,” Applied Optics, 2014, 53(3): 410–417.

[47] B. Redding, M. Alam, M. Seifert, and H. Cao, “High-resolution and broadband all-fiber spectrometers,” Optica, 2014, 1(3): 175–180.

[48] T. Wang, Y. Li, Y. Meng, Y. Qiu, and B. Mao, “Study of a fiber spectrometer based on offset fusion,” Applied Optics, 2020, 59(15): 4697–4702.

[49] T. Wang, Y. Li, B. Xu, B. Mao, Y. Qiu, and Y. Meng, “High-resolution wavemeter based on polarization modulation of fiber speckles,” APL Photonics, 2020, 5(12): 126101.

[50] G. D. Bruce, L. ODonnell, M. Chen, and K. Dholakia, “Overcoming the speckle correlation limit to achieve a fiber wavemeter with attometer resolution,” Optics Letters, 2019, 44(6): 1367–1370.

[51] G. D. Bruce, L. ODonnell, M. Chen, M. Facchin, and K. Dholakia, “Femtometer-resolved simultaneous measurement of multiple laser wavelengths in a speckle wavemeter,” Optics Letters, 2020, 45(7): 1926–1929.

[52] R. K. Gupta, G. D. Bruce, S. J. Powis, and K. Dholakia, “Deep learning enabled laser speckle wavemeter with a high dynamic range,” Laser & Photonics Reviews, 2020, 14(9): 2000120.

[53] M. Piels and D. Zibar, “Compact silicon multimode waveguide spectrometer with enhanced bandwidth,” Scientific Reports, 2017, 7: 43454.

[54] D. Yi, Y. Zhang, X. Wu, and H. K. Tsang, “Integrated multimode waveguide with photonic lantern for speckle spectroscopy,” IEEE Journal of Quantum Electronics, 2020, 57(1): 1–8.

[55] B. Redding, S. F. Liew, Y. Bromberg, R. Sarma, and H. Cao, “Evanescently coupled multimode spiral spectrometer,” Optica, 2016, 3(9): 956–962.

[56] S. F. Liew, B. Redding, M. A. Choma, H. D. Tagare, and H. Cao, “Broadband multimode fiber spectrometer,” Optics Letters, 2016, 41(9): 2029–2032.

[57] Z. Meng, J. Li, C. Yin, T. Zhang, Z. Yu, M. Tang, et al., “Multimode fiber spectrometer with scalable bandwidth using space-division multiplexing,” AIP Advances, 2019, 9(1): 015004.

[58] P. Varytis, D. N. Huynh, W. Hartmann, W. Pernice, and K. Busch, “Design study of random spectrometers for applications at optical frequencies,” Optics Letters, 2018, 43(13): 3180–3183.

[59] W. Hartmann, P. Varytis, H. Gehring, N. Walter, F. Beutel, K. Busch, et al., “Waveguide-integrated broadband spectrometer based on tailored disorder,” Advanced Optical Materials, 2020, 8(6): 1901602.

[60] W. Hartmann, P. Varytis, H. Gehring, N. Walter, F. Beutel, K. Busch, et al., “Broadband spectrometer with single-photon sensitivity exploiting tailored disorder,” Nano Letters, 2020, 20(4): 2625–2631.

[61] A. T. Young, “Rayleigh scattering,” Applied Optics, 1981, 20(4): 533–535.

[62] M. Nakazawa, “Rayleigh backscattering theory for single-mode optical fibers,” Journal of the Optical Society of America, 1983, 73(9): 1175–1180.

[63] L. Palmieri and L. Schenato, “Distributed optical fiber sensing based on Rayleigh scattering,” The Open Optics Journal, 2013, 7(1): 104–127.

[64] Y. Koshikiya, X. Fan, and F. Ito, “Long range and cm-level spatial resolution measurement using coherent optical frequency domain reflectometry with SSB-SC modulator and narrow linewidth fiber laser,” Journal of Lightwave Technology, 2008, 26(18): 3287–3294.

[65] M. D. Mermelstein, R. Posey, G. A. Johnson, and S. T. Vohra, “Rayleigh scattering optical frequency correlation in a single-mode optical fiber,” Optics Letters, 2001, 26(2): 58–60.

[66] D. Chen, Q. Liu, and Z. He, “Phase-detection distributed fiber-optic vibration sensor without fading-noise based on time-gated digital OFDR,” Optics Express, 2017, 25(7): 8315–8325.

[67] Y. Wan, S. Wang, X. Fan, Z. Zhang, and Z. He, “High-resolution wavemeter using Rayleigh speckle obtained by optical time domain reflectometry,” Optics Letters, 2020, 45(4): 799–802.

[68] S. Wang, Z. Zhang, X. Fan, B. Wang, and Z. He, “Calibration-free wavelength measurement with sub-femtometer resolution based on all-fiber Rayleigh speckles,” in 2019 Conference on Lasers and Electro-Optics (CLEO), USA, May 5–10, 2019, pp: 1–2.

[69] Z. Zhang, X. Fan, S. Wang, S. Zhao, B. Wang, Y. Wan, et al., “A novel wavemeter with 64 attometer spectral resolution based on Rayleigh speckle obtained from single-mode fiber,” Journal of Lightwave Technology, 2020, 38(16): 4548–4554.

[70] Y. Wan, X. Fan, S. Wang, Z. Zhang, S. Zhao, and Z. He, “Wavemeter capable of simultaneously achieving ultra-high resolution and broad bandwidth by using Rayleigh speckle from single mode fiber,” Journal of Lightwave Technology, 2020, 39(7): 2223–2229

[71] N. Coluccelli, M. Cassinerio, B. Redding, H. Cao, P. Laporta, and G. Galzerano, “The optical frequency comb fibre spectrometer,” Nature Communications, 2016, 7(1): 1–11.

[72] J. Ye and S. T. Cundiff, “Femtosecond optical frequency comb: principle, operation and applications,” Berlin: Springer Science & Business Media, 2005.

[73] R. French, S. Gigan, and O. L. Muskens, “Speckle-based hyperspectral imaging combining multiple scattering and compressive sensing in nanowire mats,” Optics Letters, 2017, 42(9): 1820–1823.

[74] C. C. Teng, C. Xiong, E. J. Zhang, W. M. Green, and G. Wysocki, “Adaptive thermal stabilization of an integrated photonic spectrometer using parasitic interference fringes,” Optics Letters, 2020, 45(12): 3252–3255.

[75] T. Liu and A. Fiore, “Designing open channels in random scattering media for on-chip spectrometers,” Optica, 2020, 7(8): 934–939.

[76] S. Loranger, M. Gagné, V. Lambin-Iezzi, and R. Kashyap, “Rayleigh scatter based order of magnitude increase in distributed temperature and strain sensing by simple UV exposure of optical fibre,” Scientific Reports, 2015, 5: 11177.

[77] M. Wu, X. Fan, Q. Liu, and Z. He, “Highly sensitive quasi-distributed fiber-optic acoustic sensing system by interrogating a weak reflector array,” Optics Letters, 2018, 43(15): 3594–3597.