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Amorphous Ge-Sb-Se thin films were co-sputtered from $\rm GeSe_4$GeSe4 and $\rm Sb_2\rm Se_3$Sb2Se3 targets. Depending on the film composition, linear optical properties were studied by ellipsometry. Y-27632 concentration The Kerr coefficient and two-photon absorption coefficient were estimated using Sheik-Bahae’s formalism for co-sputtered films of $\rm GeSe_4 \text – \rm Sb_2\rm Se_3$GeSe4-Sb2Se3 compared to $\rm GeSe_2\text -\rm Sb_2\rm Se_3$GeSe2-Sb2Se3 pseudo-binary system and $\rm As_2\rm Se_3$As2Se3 as reference. The Kerr coefficient was found within the range of $4.9 \unicode x2013- 21 \times 10^ – 18$4.9–21×10-18. Quantitatively by means of a figure of merit at 1.55 µm, thin films with compositions of $\rm Ge_7\rm Sb_25\rm Se_68$Ge7Sb25Se68 and $\rm Ge_9\rm Sb_20\rm Se_71$Ge9Sb20Se71 having an estimated Kerr coefficient of about $10.1 \times 10^ – 18\;\rm m^2\rm W^ – 1$10.1×10-18m2W-1 and $13.4 \times 10^ – 18\;\rm m^2\rm W^ – 1$13.4×10-18m2W-1 should be considered for the future nonlinear optical integrated platforms. Such compositions being close to $(\rm GeSe_4)_50(\rm Sb_2\rm Se_3)_50$(GeSe4)50(Sb2Se3)50 pseudo-binary (i.e., $\rm Ge_7.5\rm Sb_25.0\rm Se_67.5$Ge7.5Sb25.0Se67.5) provides just the trade-off between a high Kerr coefficient and low optical losses related to two-photon absorption.We show that a standard multimode optical fiber can act as a high-resolution ultra-compact tool to manipulate cold atoms in setups with limited optical access. Spatial light modulators allow us to generate control beams at the in-vacuum fiber end by digital optical phase conjugation. With no additional in-vacuum optics, this system reaches a $ \sim 1\;\unicodex00B5\rm m $∼1µm resolution for a transverse size of only 225 µm. As a demonstration, we use it to optically transport cold atoms towards the in-vacuum fiber end, to load them in optical microtraps, and to re-cool them in optical molasses. This work shows that the rapid progress of optics in complex media opens new, to the best of our knowledge, perspectives for spatially constrained quantum technology platforms combining cold atoms with other optical, electronic, or opto-mechanical systems.The spectral resolution of broadband Fourier-transform coherent anti-Stokes Raman spectroscopy is limited by the maximum optical path length difference that can be scanned within a short time in an interferometer. However, alternatives to the Fourier transform exist which can bypass this limitation with certain assumptions. We apply one such approach to broadband coherent Raman spectroscopy using interferometers with a short delay line (low Fourier spectral resolution) and large delay line (high Fourier spectral resolution). With this method, we demonstrate that broadband coherent Raman spectroscopy of closely spaced vibrational bands is possible using a short delay line interferometer with comparable spectral resolution to the longer delay line instrument. We discuss how this approach may be particularly useful for more complex Raman spectra, such as those measured from biological samples.We have studied the penetration of the extremely compressed wave packet-“light bullet” (LB)-through an air gap upon femtosecond single-pulse mid-IR filamentation in LiF. Applying the laser coloration method and performing numerical simulations, we have found that the single-cycle LB, which is formed before the air gap up to 0.5 mm wide, completely recovers after passing a certain distance inside LiF after the gap. This distance demonstrates nonlinear dependence on the gap width and LB pathway before the gap. We conclude that the observed self-reconstruction of the LB is caused by the high localization of the light field in the air gap due to strongly convergent wave front of the bullet, while the effect of the surrounding low-energy background of the pulse can be neglected.Image fusion is the key step to improve the performance of object detection in polarization images. We propose an unsupervised deep network to address the polarization image fusion issue. The network learns end-to-end mapping for fused images from intensity and degree of linear polarization images, without the ground truth of fused images. Customized architecture and loss function are designed to boost performance. Experimental results show that our proposed network outperforms other state-of-the-art methods in terms of visual quality and quantitative measurement.Compact and broadband non-volatile silicon devices are mainly absorption based. Hence, access to low-loss non-volatile phase shifters is still a challenge. Here, this problem is addressed by using a high-mobility transparent conducting oxide such as cadmium oxide as a floating gate in a flash-like structure. This structure is integrated in a Mach-Zehnder interferometer switch. Results show an active length of only 30 µm to achieve a $ \pi $π phase shift. Furthermore, an extinction ratio of 20 dB and insertion loss as low as 1 dB may be attained. The device shows an optical broadband response and can be controlled with low-power pulses in the nanosecond range. These results open a new, to the best of our knowledge, way for enabling compact silicon-based phase shifters with non-volatile performance.We experimentally demonstrate the use of a high-coherence hybrid silicon (Si)/III-V semiconductor laser as the light source for a transmitter generating 20 Gbaud 16- and 64- quadrature amplitude modulated (QAM) data signals over an 80 km single-mode fiber (SMF) link. The hybrid Si/III-V laser has a measured Schawlow-Townes linewidth of $\sim10\;\rm kHz$∼10kHz, which is achieved by storing modal optical energy in low-loss Si, rather than the relatively lossy III-V materials. We measure a received bit error rate (BER) of $4.1 \times 10^ – 3$4.1×10-3 when transmitting the 64-QAM data over an 80 km SMF using the hybrid Si/III-V laser. Furthermore, we measure a BER of $ \lt 1 \times 10^ – 4$ less then 1×10-4 with the Viterbi-Viterbi digital carrier phase recovery method when transmitting the 16-QAM data over an 80 km SMF using the hybrid Si/III-V laser. This performance is achieved at power penalties lower than those obtained with an exemplary distributed feedback laser and slightly higher than those with an exemplary narrow-linewidth external cavity laser.