Short range optical data links are experiencing bandwidth limitations making it very challenging to cope with the growing data transmission capacity demands. Parallel optics appears as a valid short-term solution. It is, however, not a viable solution in the long-term because of its complex optical packaging. Therefore, increasing effort is now put into the possibility of exploiting higher order modulation formats with increased spectral efficiency and reduced optical transceiver complexity. As these type of links are based on intensity modulation and direct detection, modulation formats relying on optical coherent detection can not be straight forwardly employed. As an alternative and more viable solution, this paper proposes the use of carrierless amplitude phase (CAP) in a novel multiband approach (MultiCAP) that achieves record spectral efficiency, increases tolerance towards dispersion and bandwidth limitations, and reduces the complexity of the transceiver. We report on numerical simulations and experimental demonstrations with capacity beyond 100 Gb/s transmission using a single externally modulated laser. In addition, an extensive comparison with conventional CAP is also provided. The reported experiment uses MultiCAP to achieve 102.4 Gb/s transmission, corresponding to a data payload of 95.2 Gb/s error free transmission by using a 7% forward error correction code. The signal is successfully recovered after 15 km of standard single mode fiber in a system limited by a 3 dB bandwidth of 14 GHz.

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Transparent wood is an emerging load‐bearing material reinvented from natural wood scaffolds with added light management functionalities. Such material shows promising properties for buildings and related structural applications, including its renewable and abundant origin, interesting optical properties, outstanding mechanical performance, low density, low thermal conductivity, and great potential for multifunctionalization. In this study, a detailed summary of recent progress on the transparent wood research topic is presented. Remaining questions and challenges related to transparent wood preparation, optical property measurements, and transparent wood modification and applications are discussed.

In this report, we demonstrate lasing action from a novel gain material containing organic dye Rhodamine 6G (Rh6G) embedded into transparent wood (TW) matrix. Besides the unusual origin and appearance of the investigated material, it has numerous advantages defined by the properties of components used for its fabrication. Organic dyes are of special interest as active media due to their broadband emission/absorption spectra and very high optical gain. [13][14][15] Transparent wood features light weight, modification accessibility, excellent mechanical performance, and structural anisotropy introduced by aligned hollow cells. [16,17] Optical transparency of TW is the most unique property, which extends its applications in various fields, including biosciences, lighting, building industry, and others. [17][18][19] Although this material (TW) is relatively new, it has already been tested for potential applications in optics, but so far only for implementation in passive photonic components. [18] However, due to its compatibility with polymer technology, TW is an interesting alternative for applications requiring optical activity, first of all lasing, where demanded materials should be inexpensive, easily handled and disposable. Material Preparation and CharacterizationAs the TW itself does not possess any optical gain, a host matrix should be "activated" with an additional optically active medium, Rh6G dye in our case. The samples with dye embedded into TW structure were prepared in three technological steps (Figure 1). At the first step, balsa wood (Ochroma pyramidale, purchased from Wentzels Co. Ltd, Sweden) of thickness of 1.0 mm and 3.0 mm was delignified using 1 wt% of sodium chlorite (NaClO 2 , Sigma-Aldrich) in acetate buffer solution (pH 4.6) at 80 °C, until the wood was totally bleached. Then the delignified wood was dehydrated with ethanol and acetone, sequentially; each procedure was repeated three times. At the second step, wood template was put in dye (Rh6G 99%, SIGMA-ALDRICH) acetone solution with a concentration of 1 × 10 −3 mole/L. Finally, the wood template was fully infiltrated into the pre-polymerized MMA solution and then cured at 75 °C for 4 h.The surface and cross-sections of the TW samples were investigated with a field-emission scanning electron microscope (Hitachi S-4800, Japan) operating at an acceleration voltage of 1 kV. The samples were roughly polished and coated with Pt/Pd before SEM imaging. The length of fibers constituting the wood material varies in range of 200-1000 µm, whereas the lumen The report on a study of laser emission from a conceptually new organic material based on transparent wood (TW) with embedded dye Rhodamine 6G molecules is presented in this paper. The lasing performance is compared to a reference organic material containing dye in a poly-methyl-methacrylate matrix. From experimental results, one can conclude that the optical feedback in dye-TW material is realized within cellulose fibers, which play the role of tiny optical resonators. Therefore, the output emis...

Thiol-ene polymer/Si nanocrystal bulk hybrids were synthesized from alkyl-passivated Si nanocrystal (Si NC) toluene solutions. Radicals in the polymer provided a copassivation of "dark" Si NCs, making them optically active and leading to a substantial ensemble quantum yield increase. Optical stability over several months was confirmed. The presented materials exhibit the highest photoluminescence quantum yield (∼65%) of any solid-state Si NC hybrid reported to date. The broad tunability of thiol-ene polymer reactivity provides facile glass integration, as demonstrated by a laminated structure. This, together with extremely fast polymerization, makes the demonstrated hybrid material a promising candidate for light converting applications.