SPIE LASE最新文献

{"title":"Multi-scale nonlinear effects in whispering-gallery mode resonators","authors":"G. Lin, S. Diallo, Y. Chembo","doi":"10.1117/12.2212002","DOIUrl":"https://doi.org/10.1117/12.2212002","url":null,"abstract":"Whispering gallery mode resonators have been the focus of many research works in recent years. They allow to study the light-matter interactions induced by the confinement of photons in nonlinear media. In particular, Brillouin Raman and Kerr nonlinearities excite the resonator at the lattice, molecular and electronic scale. This difference in spatial scales give to whispering gallery-mode resonators the potential to be central photonic components in microwave photonics, quantum optics and optoelectronics. We discuss in this communication some of the key challenges that have to be met for the understanding of Kerr, Raman and Brillouin interactions that can take place in these resonators.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114386081","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Packaging of fiber lasers and components for use in harsh environments","authors":"D. Creeden, B. Johnson, Casey Jones, C. Ibach, M. Lemons, P. Budni, James P. Zona, Adam J. Marcinuk, C. Willis, J. Sweeney, S. Setzler","doi":"10.1117/12.2209101","DOIUrl":"https://doi.org/10.1117/12.2209101","url":null,"abstract":"High power continuous and pulsed fiber lasers and amplifiers have become more prevalent in laser systems over the last ten years. In fielding such systems, strong environmental and operational factors drive the packaging of the components. These include large operational temperature ranges, non-standard wavelengths of operation, strong vibration, and lack of water cooling. Typical commercial fiber components are not designed to survive these types of environments. Based on these constraints, we have had to develop and test a wide range of customized fiber-based components and systems to survive in these conditions. In this paper, we discuss some of those designs and detail the testing performed on those systems and components. This includes the use of commercial off-the-shelf (COTS) components, modified to survive extended temperature ranges, as well as customized components designed specifically for performance in harsh environments. Some of these custom components include: ruggedized/monolithic fiber spools; detachable and repeatable fiber collimators; low loss fiber-to-fiber coupling schemes; and high power fiber-coupled isolators.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"6 2","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120910451","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"High power coatings for line beam laser optics of up to 2-meter in length","authors":"M. Mende, Jürgen Kohlhaas, W. Ebert","doi":"10.1117/12.2218436","DOIUrl":"https://doi.org/10.1117/12.2218436","url":null,"abstract":"Laser material processing plays an important role in the fabrication of the crucial parts for state-of-the-art smartphones and tablets. With industrial line beam systems a line shaped beam with a length above one meter and an average power of several thousand watts can be realized. To ensure excellent long axis beam homogeneity, demanding specifications regarding the substrate surface form tolerances and the coating uniformity have to be achieved for each line beam optic. In addition, a high laser damage threshold and a low defect density are required for the coatings. In order to meet these requirements, the MAXIMA ion beam sputtering machine was developed and built by LASEROPTIK. This contribution describes the functional principle of MAXIMA deposition machine, which adapts the ion beam sputtering technology with its highest coating quality to the field of large area deposition. Furthermore, recent developments regarding the process control by optical broadband monitoring are discussed. Finally experimental results on different thin film characteristics as for example the coating uniformity, the microstructure and the laser damage resistance of multilayers are presented.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"186 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123315788","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Plasma and laser kinetics and field emission from carbon nanotube fibers for an Advanced Noble Gas Laser (ANGL)","authors":"P. Moran, N. Lockwood, M. Lange, D. Hostutler, E. Guild, Matthew R. Guy, J. E. McCord, G. Pitz","doi":"10.1117/12.2214790","DOIUrl":"https://doi.org/10.1117/12.2214790","url":null,"abstract":"A metastable argon laser operating at 912 nm has been demonstrated by optically pumping with a pulsed titanium sapphire laser to investigate the temporal dynamics of an Advanced Noble Gas Laser (ANGL). Metastable argon concentrations on the order of 1011 cm-3 were maintained with the use of a radio frequency (RF) capacitively coupled discharge. The end-pumped laser produced output powers under 2 mW of average power with pulse lengths on the order of 100 ns. A comparison between empirical results and a four level laser model using longitudinally average pump and inter-cavity intensities is made. An alternative, highly-efficient method of argon metastable production for ANGL was explored using carbon nanotube (CNT) fibers.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131937178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Engineering of freeform refractive and reflective slow axis collimation solutions","authors":"H. Forrer, H. Moser, M. Huber, R. Schlaginhaufen, D. Kura, M. Forrer","doi":"10.1117/12.2213370","DOIUrl":"https://doi.org/10.1117/12.2213370","url":null,"abstract":"High power diode laser arrays or single emitters require either fast or slow axis optical collimation, or both, for further transport or photonic application of high power laser radiation. With varying requirements and conditions for the slow axis collimation and the corresponding engineering solutions, a multitude of options exist from spherical refractive to freeform reflective in single lens elements or in array forms. Here we report on the benefits of reflective slow axis freeform optics and its implementation for the collimation with integrated right angle reflection for compact solutions and miniaturization of module packaging.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126727896","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Broadband 7 microns OPCPA pumped by a 2 microns picosecond Ho:YLF CPA system","authors":"D. Sanchez, M. Hemmer, M. Baudisch, J. Biegert, O. Chalus, C. Simon-Boisson, K. Zawilski, P. Schunemann, V. Smirnov, H. Hoogland","doi":"10.1117/12.2213136","DOIUrl":"https://doi.org/10.1117/12.2213136","url":null,"abstract":"The development of coherent light sources with emission in the mid-IR is currently undergoing a remarkable revolution. The mid-IR spectral range has always been of tremendous interest, mainly to spectroscopists, due to the ability of mid-IR light to access rotational and vibrational resonances of molecules which give rise to superb sensitivity upon optical probing [1-3]. Previously, high energy resolution was achieved with narrowband lasers or parametric sources, but the advent of frequency comb sources has revolutionized spectroscopy by providing high energy resolution within the frequency comb structure of the spectrum and at the same time broadband coverage and short pulse duration [4-6]. Such carrier to envelope phase (CEP) controlled light waveforms, when achieved at ultrahigh intensity, give rise to extreme effects such as the generation of isolated attosecond pulses in the vacuum to extreme ultraviolet range (XUV) [7]. Motivated largely by the vast potential of attosecond science, the development of ultraintense few-cycle and CEP stable sources has intensified [8], and it was recognized that coherent soft X-ray radiation could be generated when driving high harmonic generation (HHG) with long wavelength sources [9-11]. Recently, based on this concept, the highest waveform controlled soft X-ray flux [12] and isolated attosecond pulse emission at 300 eV [13] was demonstrated via HHG from a 1850 nm, sub-2-cycle source [14]. Within strong field physics, long wavelength scaling may lead to further interesting physics such as the direct reshaping of the carrier field [15], scaling of quantum path dynamics [16], the breakdown of the dipole approximation [17] or direct laser acceleration [18]. The experimental development of long wavelength light sources therefore holds great promise in many fields of science and will lead to numerous applications beyond strong field physics and attosecond science. In this paper, we present the first mid-IR optical parametric chirped pulse amplifier (OPCPA) operating at a center wavelength of 7 μm with output parameters suitable already for strong-field experiments. It is also the first demonstration of an Optical Parametric Chirped Pulse Amplifier (OPCPA) using a 2 μm laser pump source which enables the use of non-oxide nonlinear crystals with typically limited transparency at 1 mm wavelength. This new OPCPA system is all-optically synchronized and generates 0.55 mJ energy, CEP stable optical pulses. The pulses are currently compressed to sub-8 optical cycles but support a sub-4 cycle pulse duration. The discrepancy in compression is due to uncompensated higher order phase from the grating compressor which will be addressed in the future.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"9730 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129617599","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A burst-mode photon counting receiver with automatic channel estimation and bit rate detection","authors":"H. Rao, C. Devoe, A. S. Fletcher, I. Gaschits, F. Hakimi, S. Hamilton, N. Hardy, John G. Ingwersen, R. Kaminsky, J. Moores, M. Scheinbart, T. Yarnall","doi":"10.1117/12.2222885","DOIUrl":"https://doi.org/10.1117/12.2222885","url":null,"abstract":"We demonstrate a multi-rate burst-mode photon-counting receiver for undersea communication at data rates up to 10.416 Mb/s over a 30-foot water channel. To the best of our knowledge, this is the first demonstration of burst-mode photon-counting communication. With added attenuation, the maximum link loss is 97.1 dB at λ=517 nm. In clear ocean water, this equates to link distances up to 148 meters. For λ=470 nm, the achievable link distance in clear ocean water is 450 meters. The receiver incorporates soft-decision forward error correction (FEC) based on a product code of an inner LDPC code and an outer BCH code. The FEC supports multiple code rates to achieve error-free performance. We have selected a burst-mode receiver architecture to provide robust performance with respect to unpredictable channel obstructions. The receiver is capable of on-the-fly data rate detection and adapts to changing levels of signal and background light. The receiver updates its phase alignment and channel estimates every 1.6 ms, allowing for rapid changes in water quality as well as motion between transmitter and receiver. We demonstrate on-the-fly rate detection, channel BER within 0.2 dB of theory across all data rates, and error-free performance within 1.82 dB of soft-decision capacity across all tested code rates. All signal processing is done in FPGAs and runs continuously in real time.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128621649","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reducing residual stresses and deformations in selective laser melting through multi-level multi-scale optimization of cellular scanning strategy","authors":"S. Mohanty, J. Hattel","doi":"10.1117/12.2212490","DOIUrl":"https://doi.org/10.1117/12.2212490","url":null,"abstract":"Residual stresses and deformations continue to remain one of the primary challenges towards expanding the scope of selective laser melting as an industrial scale manufacturing process. While process monitoring and feedback-based process control of the process has shown significant potential, there is still dearth of techniques to tackle the issue. Numerical modelling of selective laser melting process has thus been an active area of research in the last few years. However, large computational resource requirements have slowed the usage of these models for optimizing the process. In this paper, a calibrated, fast, multiscale thermal model coupled with a 3D finite element mechanical model is used to simulate residual stress formation and deformations during selective laser melting. The resulting reduction in thermal model computation time allows evolutionary algorithm-based optimization of the process. A multilevel optimization strategy is adopted using a customized genetic algorithm developed for optimizing cellular scanning strategy for selective laser melting, with an objective of reducing residual stresses and deformations. The resulting thermo-mechanically optimized cellular scanning strategies are compared with standard scanning strategies and have been used to manufacture standard samples.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115177533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Repurposing mainstream CNC machine tools for laser-based additive manufacturing","authors":"Jason B. Jones","doi":"10.1117/12.2217901","DOIUrl":"https://doi.org/10.1117/12.2217901","url":null,"abstract":"The advent of laser technology has been a key enabler for industrial 3D printing, known as Additive Manufacturing (AM). Despite its commercial success and unique technical capabilities, laser-based AM systems are not yet able to produce parts with the same accuracy and surface finish as CNC machining. To enable the geometry and material freedoms afforded by AM, yet achieve the precision and productivity of CNC machining, hybrid combinations of these two processes have started to gain traction. To achieve the benefits of combined processing, laser technology has been integrated into mainstream CNC machines - effectively repurposing them as hybrid manufacturing platforms. This paper reviews how this engineering challenge has prompted beam delivery innovations to allow automated changeover between laser processing and machining, using standard CNC tool changers. Handling laser-processing heads using the tool changer also enables automated change over between different types of laser processing heads, further expanding the breadth of laser processing flexibility in a hybrid CNC. This paper highlights the development, challenges and future impact of hybrid CNCs on laser processing.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129981567","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Experimental study on Ti alloy plate fabrication by vacuum selective laser melting","authors":"Yuji Sato, M. Tsukamoto, Y. Yamashita, S. Masuno, N. Abe","doi":"10.1117/12.2212654","DOIUrl":"https://doi.org/10.1117/12.2212654","url":null,"abstract":"We demonstrated that a Ti-6Al-4V plate, which is clinically used for artificial bone and hard tissue implant in human body because of their light and biocompatibility, were fabricated by SLM process in vacuum. The chamber’s pressure was set to 1.0×10-3 Pa to prevent the Ti64 powder from oxidizing. The base plate of the powder bed was vertically dropped in determined steps, and Ti64 powder supplied from the powder feeder was then smoothed by a roller on top of the powder bed. The single-mode fiber laser irradiated and melted the powder bed to make a molten pool in order to form 2D metallic structures In order to investigate the laser melting and solidification dynamics, a process of Ti 64 plate fabrication was captured by high speed video camera. It was also determined that crystal orientation was evaluated with X-ray diffraction (XRD) and energy dispersive X-ray (EDX) spectroscopy From EDX analysis, the chemical compounds were not changed from powder to fabricated sample. And it was recorded from the powder peaks of α (1011), α (0002), α (1010), and α (1012) that the crystal orientation is composed mainly of martensitic alpha by XRD analysis. Diffraction peaks corresponding to β (110) were detected in vacuum SLM processed samples.","PeriodicalId":314691,"journal":{"name":"SPIE LASE","volume":"60 2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2016-04-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133550601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}