High-resolution and broadband all-fiber spectrometers

Figure from this press release.

We recently talked about strange PSFs such as that one found in the Universe, or that of the Rambus chip or that diffusive natural medium, here is another one: Fiber optics that can be used to do what we generally expect hyperspectral cameras to do.

High-resolution and broadband all-fiber spectrometers by Brandon Redding, Mansoor Alam, Martin Seifert, Hui Cao

The development of optical fibers has revolutionized telecommunications by enabling long-distance broad-band transmission with minimal loss. In turn, the ubiquity of high-quality low-cost fibers enabled a number of additional applications, including fiber sensors, fiber lasers, and imaging fiber bundles. Recently, we showed that a mutlimode optical fiber can also function as a spectrometer by measuring the wavelength-dependent speckle pattern formed by interference between the guided modes. Here, we reach a record resolution of 1 pm at wavelength 1500 nm using a 100 meter long multimode fiber, outperforming the state-of-the-art grating spectrometers. we also achieved broad-band operation with a 4 cm long fiber, covering 400 nm - 750 nm with 1 nm resolution. The fiber spectrometer, consisting of the fiber which can be coiled to a small volume and a monochrome camera that records the speckle pattern, is compact, lightweight, and low cost while providing ultrahigh resolution, broad bandwidth and low loss.

Compact spectrometer based on a disordered photonic chip by Brandon Redding, Seng Fatt Liew, Raktim Sarma and Hui Cao

Light scattering in disordered media has been studied extensively due to its prevalence in natural and artificial systems. In photonics most of the research has focused on understanding and mitigating the effects of scattering, which are often detrimental. For certain applications, however, intentionally introducing disorder can actually improve device performance, as in photovoltaics. Here, we demonstrate a spectrometer based on multiple light scattering in a silicon-on-insulator chip featuring a random structure. The probe signal diffuses through the chip generating wavelength-dependent speckle patterns, which are detected and used to recover the input spectrum after calibration. A spectral resolution of 0.75 nm at a wavelength of 1,500 nm in a 25-μm-radius structure is achieved. Such a compact, high-resolution spectrometer is well suited for lab-on-a-chip spectroscopy applications.

On-chip random spectrometer by B. Redding ; S. F. Liew ; R. Sarma ; H. Cao

also relevant:

172. A. Basiri, Y. Bromberg, A. Yamilov, H. Cao, and T. Kottos, "Light localization induced by a random imaginary refractive index", Phys. Rev. A , vol. 90, 043815, 2014. [Click here to Download]
171. Brandon Redding, Mansoor Alam, Martin Seifert, and Hui Cao, "High-resolution and broadband all-fiber spectrometers", Optica , vol. 1, 175, 2014. [Click here to Download]
169. Raktim Sarma, Timofey Golubev, Alexey Yamilov, and Hui Cao, "Control of light diffusion in a disordered photonic waveguide", Appl. Phys. Lett. , vol. 105, 041104, 2014. [Click here to Download]
164. Seng Fatt Liew, Sebastien M. Popoff, Allard P. Mosk, Willem L. Vos and Hui Cao, "Transmission channels for light in absorbing random media: From diffusive to ballistic-like transport", Phys. Rev. B , vol. 89, 224202, 2014. [Click here to Download]
162. Yaron Bromberg and Hui Cao, "Generating Non-Rayleigh Speckles with Tailored Intensity Statistics", Phys. Rev. Lett. , vol. 112, 213904, 2014. [Click here to Download]
160. S. M. Popoff, A. Goetschy, S. F. Liew, A. D. Stone, and H. Cao, "Coherent Control of Total Transmission of Light through Disordered Media", Phys. Rev. Lett. , vol. 112, 133903, 2014. [Click here to Download]
157. Brandon Redding, Sebastien M. Popoff, Yaron Bromberg, Michael A. Choma, and Hui Cao "Noise analysis of spectrometers based on speckle pattern reconstruction," Applied Optics vol. 53, 410, 2014. [Click here to Download]
152. Brandon Redding, Seng Fatt Liew, Raktim Sarma and Hui Cao, "Compact spectrometer based on disordered photonic chip", Nature Photonics, vol. 7 , 746, 2013. [Click here to Download]
H. Cao, Review on Latest developments in random lasers with coherent feedback, J. Phys. A: Math. Gen., vol. 38, pp. 10497-10535, Nov. 2005. [Click here to Download]
H. Cao, Random lasers: development, features, and applications, Opt. Photon. News, vol. 16, pp. 24-29, Jan. 2005. [Click here to Download]
H. Cao, Lasing in Random Media, Waves in Random Media, vol. 13, pp. R1-R39, June 2003. [Click here to Download]

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