| 1 | High spectro-temporal compression on a nonlinear CMOS-chip显示文摘Optical pulses are fundamentally defined by their temporal and spectral properties.The ability to control pulse properties allows practitioners to efficiently leverage them for advanced metrology,high speed optical communications and attosecond science.Here,we report 11×temporal compression of 5.8 ps pulses to 0.55 ps using a low power of 13.3 W.The result is accompanied by a significant increase in the pulse peak power by 9.4×.These results represent the strongest temporal compression demonstrated to date on a complementary metal–oxide–semiconductor(CMOS)chip.In addition,we report the first demonstration of on-chip spectral compression,3.0×spectral compression of 480 fs pulses,importantly while preserving the pulse energy.The strong compression achieved at low powers harnesses advanced on-chip device design,and the strong nonlinear properties of backend-CMOS compatible ultra-silicon-rich nitride,which possesses absence of two-photon absorption and 500×larger nonlinear parameter than in stoichiometric silicon nitride waveguides.The demonstrated work introduces an important new paradigm for spectro-temporal compression of optical pulses toward turn-key,on-chip integrated systems for all-optical pulse control. | Ju Won Choi Ezgi Sahin Byoung-Uk Sohn George F.R.Chen Doris K.T.Ng Anuradha M.Agarwal Lionel C.Kimerling Dawn T.H.Tan | 2021 | Light(Science & Applications)2021，10，7： | 0 |
| 2 | Thermo-optically tunable spectral broadening in a nonlinear ultra-silicon-rich nitride Bragg grating显示文摘Spectral tunability methods used in optical communications and signal processing leveraging optical,electrical,and acousto-optic effects typically involve spectral truncation that results in energy loss.Here we demonstrate temperature tunable spectral broadening using a nonlinear ultra-silicon-rich nitride device consisting of a 3-mm-long cladding-modulated Bragg grating and a 7-mm-long nonlinear channel waveguide.By operating at frequencies close to the grating band edge,in an apodized Bragg grating,we access strong grating-induced dispersion while maintaining low losses and high transmissivity.We further exploit the redshift in the Bragg grating stopband due to the thermo-optic effect to achieve tunable dispersion,leading to varying degrees of soliton-effect compression and self-phase-modulation-induced spectral broadening.We observe an increase in the bandwidth of the output pulse spectrum from 69 to 106 nm as temperature decreases from 70℃ to 25℃,in good agreement with simulated results using the generalized nonlinear Schrödinger equation.The demonstrated approach provides a new avenue to achieve on-chip laser spectral tuning without loss in pulse energy. | Yanmei Cao Ezgi Sahin Ju Won Choi Peng Xing George F.R.Chen D.K.T.Ng Benjamin J.Eggleton Dawn T.H.Tan | 2021 | Photonics Research2021，9，4： | 0 |
| 4 | The in-vivo assessment of Turkish propolis and its nano form on testicular damage induced by cisplatin显示文摘Objective: Chemotherapeutic drugs, such as cisplatin(CP), which are associated with oxidative stress and apoptosis, may adversely affect the reproductive system. This study tests whether administration of propolis and nano-propolis(NP) can alleviate oxidative stress and apoptosis in rats with testicular damage induced by CP.Methods: In this study, polymeric nanoparticles including propolis were synthesized with a green sonication method and characterized using Fourier transform-infrared spectroscopy, Brunauer-EmmettTeller, and wet scanning transmission electron microscopy techniques. In total, 56 rats were divided into the following seven groups: control, CP, propolis, NP-10, CP + propolis, CP + NP-10, and CP + NP-30.Propolis(100 mg/kg), NP-10(10 mg/kg), and NP-30(30 mg/kg) treatments were administered by gavage daily for 21 d, and CP(3 mg/kg) was administered intraperitoneally in a single dose. After the experiment,oxidative stress parameters, namely, malondialdehyde(MDA), glutathione(GSH), glutathione peroxidase(GPx), and catalase(CAT), and apoptotic pathways including B cell leukemia/lymphoma-2 protein(Bcl-2)and Bcl-2-associated X protein(Bax) were measured in testicular tissues. Furthermore, sperm quality and weights of the testis, epididymis, right cauda epididymis, seminal vesicles and prostate were evaluated.Results: Propolis and NP(especially NP-30) were able to preserve oxidative balance(decreased MDA levels and increased GSH, CAT, and GPx activities) and activate apoptotic pathways(decreased Bax and increased Bcl-2) in the testes of CP-treated rats. Sperm motility in the control, CP, and CP + NP-30 groups were 60%, 48.75%, and 78%, respectively(P<0.001). Especially, NP-30 application completely corrected the deterioration in sperm features induced by CP.Conclusion: The results show that propolis and NP treatments mitigated the side effects of CP on spermatogenic activity, antioxidant situation, and apoptosis in rats. | Pinar Tatli Seven Ismail Seven Selcan Karakus Seda Iflazoglu Mutlu Seyma Ozer Kaya Gozde Arkali Merve Ilgar Ezgi Tan Yesim Muge Sahin Deniz Ismik Ayben Kilislioglu | 2021 | Journal of Integrative Medicine2021，19，5： | 0 |
您所在的机构暂未开通此部分的功能，请联系管理员