Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5943307
M. Hamamda, T. Taillandier-Loize, F. Péralès, G. Dutier, M. Gorza, J. Baudon, M. Ducloy
Metastable argon atoms Ar*(3P2), produced by electron bombardment of a nozzle beam of ground state Ar atoms, are slowed down from their initial thermal velocity of 560 m/s down to a few tens of m/s, using a standard Zeeman slower. In this decelerator [1], a repulsive force is induced by a counter-propagating σ+-polarized laser beam, locked in frequency on the 3P2-3D3 closed transition (λ = 811.5 nm) and then detuned by 340 MHz. A special profile of longitudinal magnetic field is adjusted in order to maintain atoms in resonance with light all over the device, by compensating the variable Doppler shift by the convenient Zeeman shift. Low velocities, e.g. 55 m/s, are accessible but due to spontaneous emission randomly distributed recoil momentums enlarge both angular and velocity distributions of the beam [2]. Nevertheless, by placing off axis collimating slits and grating, it is in principle possible to observe transmission and/or diffraction phenomena specific of low velocities.
{"title":"Van der Waals - Zeeman transitions of slow metastable argon atoms Ar*(3P2)","authors":"M. Hamamda, T. Taillandier-Loize, F. Péralès, G. Dutier, M. Gorza, J. Baudon, M. Ducloy","doi":"10.1109/CLEOE.2011.5943307","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943307","url":null,"abstract":"Metastable argon atoms Ar*(3P2), produced by electron bombardment of a nozzle beam of ground state Ar atoms, are slowed down from their initial thermal velocity of 560 m/s down to a few tens of m/s, using a standard Zeeman slower. In this decelerator [1], a repulsive force is induced by a counter-propagating σ+-polarized laser beam, locked in frequency on the 3P2-3D3 closed transition (λ = 811.5 nm) and then detuned by 340 MHz. A special profile of longitudinal magnetic field is adjusted in order to maintain atoms in resonance with light all over the device, by compensating the variable Doppler shift by the convenient Zeeman shift. Low velocities, e.g. 55 m/s, are accessible but due to spontaneous emission randomly distributed recoil momentums enlarge both angular and velocity distributions of the beam [2]. Nevertheless, by placing off axis collimating slits and grating, it is in principle possible to observe transmission and/or diffraction phenomena specific of low velocities.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79155402","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}
Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5943623
M. Schnell, P. Alonso‐González, F. Casanova, L. Arzubiaga, L. Hueso, A. Chuvilin, R. Hillenbrand
Metal antennas and transmission lines are common devices for receiving and transporting signals in the radiofrequency regime. Here, we demonstrate that by reducing the size down to the micrometer range, these devices can be operated at infrared frequencies (∼30 THz) [1,2]. We apply our recently introduced vector near-field microscopy technique [3] for directly visualizing the reception and transport of infrared energy [4]. The combination of antenna plus transmission line is a promising platform technology for designing future mid-infrared devices which require subwavelength-scale integration.
{"title":"Mid-infrared nanophotonics based on antennas and transmission lines","authors":"M. Schnell, P. Alonso‐González, F. Casanova, L. Arzubiaga, L. Hueso, A. Chuvilin, R. Hillenbrand","doi":"10.1109/CLEOE.2011.5943623","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943623","url":null,"abstract":"Metal antennas and transmission lines are common devices for receiving and transporting signals in the radiofrequency regime. Here, we demonstrate that by reducing the size down to the micrometer range, these devices can be operated at infrared frequencies (∼30 THz) [1,2]. We apply our recently introduced vector near-field microscopy technique [3] for directly visualizing the reception and transport of infrared energy [4]. The combination of antenna plus transmission line is a promising platform technology for designing future mid-infrared devices which require subwavelength-scale integration.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79165837","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}
Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5942816
K. Tada, N. Karasawa
Coherent anti-Stokes Raman scattering (CARS) spectroscopy is one of the nonlinear Raman spectroscopy and is attracting attention recently because in CARS spectroscopy, fluorescence can be avoided, the spatial resolution is high, and the exposure time is short. Generally, two separate beams, a pump beam and a Stokes beam, have to be collinearly overlapped and focused on a sample using an objective lens in CARS. However, the adjustments of these two beams, necessary to generate strong CARS signals, are not easy in general. In this paper, we demonstrate a novel setup for single oscillator CARS spectroscopy using a single beam, where a Stokes pulse and a pump pulse are generated by the combination of a pulse shaper and a photonic crystal fiber (PCF). In this setup, two pulses, one for generating a wavelength-tunable fundamental soliton pulse [1], and the other for generating a narrowband pump pulse, are shaped by a pulse shaper and are inputted in a PCF. Especially, the pulse for a pump pulse is negatively-chirped by a pulse shaper for the spectral compression in a PCF [2], which is important to obtain a narrowband pump pulse to obtain the high spectral resolution while retaining most of the pulse energy. In this setup, the pulse is shaped before it is inputted in a PCF to create Stokes and pump pulses suitable for CARS spectroscopy, and is different from previous studies for single-beam CARS spectroscopy, where a broadband pulse that contains both Stokes and pump components is shaped to obtain CARS signals [3,4].
{"title":"Single-beam CARS spectroscopy using a soliton Stokes pulse and a spectrally-compressed pump pulse from a PCF","authors":"K. Tada, N. Karasawa","doi":"10.1109/CLEOE.2011.5942816","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942816","url":null,"abstract":"Coherent anti-Stokes Raman scattering (CARS) spectroscopy is one of the nonlinear Raman spectroscopy and is attracting attention recently because in CARS spectroscopy, fluorescence can be avoided, the spatial resolution is high, and the exposure time is short. Generally, two separate beams, a pump beam and a Stokes beam, have to be collinearly overlapped and focused on a sample using an objective lens in CARS. However, the adjustments of these two beams, necessary to generate strong CARS signals, are not easy in general. In this paper, we demonstrate a novel setup for single oscillator CARS spectroscopy using a single beam, where a Stokes pulse and a pump pulse are generated by the combination of a pulse shaper and a photonic crystal fiber (PCF). In this setup, two pulses, one for generating a wavelength-tunable fundamental soliton pulse [1], and the other for generating a narrowband pump pulse, are shaped by a pulse shaper and are inputted in a PCF. Especially, the pulse for a pump pulse is negatively-chirped by a pulse shaper for the spectral compression in a PCF [2], which is important to obtain a narrowband pump pulse to obtain the high spectral resolution while retaining most of the pulse energy. In this setup, the pulse is shaped before it is inputted in a PCF to create Stokes and pump pulses suitable for CARS spectroscopy, and is different from previous studies for single-beam CARS spectroscopy, where a broadband pulse that contains both Stokes and pump components is shaped to obtain CARS signals [3,4].","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79335173","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}
Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5942539
S. Chaitanya Kumar, G. K. Samanta, K. Devi, S. Sanguinetti, M. Ebrahim-Zadeh
The titanium-doped sapphire (Ti:Al2O3) laser has been established as the workhorse tunable solid-state laser for the near-infrared spectral range, for continuous-wave (cw) as well as ultrafast timescales, benefiting numerous applications. Ti:sapphire laser have relied mainly on argon ion lasers and frequency-doubled Nd-based green lasers as the pump source [1]. Other possible pumps include optically-pumped-semiconductor-lasers in the green, employing intracavity frequency-doubling and, more recently, GaN diode lasers in the blue, but with limitations of low output power and poor beam quality. Fiber lasers have recently attracted much attention for their compact design, robustness, power scalability with turnkey operation and cost effectiveness. The combination of a cw infrared fiber laser and a simple single-pass second-harmonic-generation scheme based on MgO:sPPLT is a potentially attractive route for high-power cw green generation [2]. Hence, it is worthwhile to explore its potential as a new pump architecture for the Ti:sapphire laser, which would provide a simple, high-power, compact, and cost-effective alternative to the traditional, cw solid-state green sources.
{"title":"High-power, single-frequency Ti:sapphire laser pumped by a continuous-wave fiber laser green source","authors":"S. Chaitanya Kumar, G. K. Samanta, K. Devi, S. Sanguinetti, M. Ebrahim-Zadeh","doi":"10.1109/CLEOE.2011.5942539","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942539","url":null,"abstract":"The titanium-doped sapphire (Ti:Al2O3) laser has been established as the workhorse tunable solid-state laser for the near-infrared spectral range, for continuous-wave (cw) as well as ultrafast timescales, benefiting numerous applications. Ti:sapphire laser have relied mainly on argon ion lasers and frequency-doubled Nd-based green lasers as the pump source [1]. Other possible pumps include optically-pumped-semiconductor-lasers in the green, employing intracavity frequency-doubling and, more recently, GaN diode lasers in the blue, but with limitations of low output power and poor beam quality. Fiber lasers have recently attracted much attention for their compact design, robustness, power scalability with turnkey operation and cost effectiveness. The combination of a cw infrared fiber laser and a simple single-pass second-harmonic-generation scheme based on MgO:sPPLT is a potentially attractive route for high-power cw green generation [2]. Hence, it is worthwhile to explore its potential as a new pump architecture for the Ti:sapphire laser, which would provide a simple, high-power, compact, and cost-effective alternative to the traditional, cw solid-state green sources.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84929115","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}
Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5942641
M. Duhant, W. Renard, G. Canat, C. Planchat, F. Smektala, J. Troles, P. Bourdon
Supercontinuum sources in the mid-infrared may found many potential applications to spectroscopy and material caracterization. Supercontinuum light extending up to 4000 nm has been efficiently generated in fluorozirconate glasses (ZBLAN) with 10.5 W power using an amplified nanosecond pulsed laser diode at 1550 nm [1]. As the dispersion wavelength of the fiber is closed to 1700 nm, pumping at 1550 nm does not directly allow generation of solitons. A first approach is thus to pump a piece of SMF fiber in the anomalous dispersion regime to generate the solitons and shift them to the anomalous dispersion regime of the ZBLAN fiber [1,2]. Another approach is to use a high power femtosecond laser at 1600 nm [3]. In that case, the pulse broadens through self phase modulation up to overlap with the ZBLAN anomalous dispersion regime. In both cases, the pump wavelength is very closed to the zero dispersion wavelength of the fiber to maximize the spectrum broadening. However, a limited amount of power is generated beyond 2500 nm (30%) which is the relevant spectral window for many applications. Here we report on what we believe to be the first demonstration of direct pumping of ZBLAN in the anomalous dispersion regime at 2 µm to generate a supercontinuum extending up to 3800 nm.
{"title":"Improving mid-infrared supercontinuum generation efficiency by pumping a fluoride fiber directly into the anomalous regime at 1995 nm","authors":"M. Duhant, W. Renard, G. Canat, C. Planchat, F. Smektala, J. Troles, P. Bourdon","doi":"10.1109/CLEOE.2011.5942641","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942641","url":null,"abstract":"Supercontinuum sources in the mid-infrared may found many potential applications to spectroscopy and material caracterization. Supercontinuum light extending up to 4000 nm has been efficiently generated in fluorozirconate glasses (ZBLAN) with 10.5 W power using an amplified nanosecond pulsed laser diode at 1550 nm [1]. As the dispersion wavelength of the fiber is closed to 1700 nm, pumping at 1550 nm does not directly allow generation of solitons. A first approach is thus to pump a piece of SMF fiber in the anomalous dispersion regime to generate the solitons and shift them to the anomalous dispersion regime of the ZBLAN fiber [1,2]. Another approach is to use a high power femtosecond laser at 1600 nm [3]. In that case, the pulse broadens through self phase modulation up to overlap with the ZBLAN anomalous dispersion regime. In both cases, the pump wavelength is very closed to the zero dispersion wavelength of the fiber to maximize the spectrum broadening. However, a limited amount of power is generated beyond 2500 nm (30%) which is the relevant spectral window for many applications. Here we report on what we believe to be the first demonstration of direct pumping of ZBLAN in the anomalous dispersion regime at 2 µm to generate a supercontinuum extending up to 3800 nm.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84947347","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}
Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5943232
M. Malinauskas, D. Baltriukienė, Antanas Kraniauskas, P. Danilevičius, E. Balčiūnas, A. Žukauskas, V. Purlys, R. Širmenis, V. Bukelskiene, R. Gadonas, V. Sirvydis, A. Piskarskas
In this report we present experimental results on biocompatibility based on stem cell growth experiments in vitro as well as reaction of living organism to polymer implants in vivo of femtosecond laser 3D micro/nanostructurable photopolymers. A synergetic study on materials for rapid 3D scaffold fabrication having micrometer features and being centimeter in size, their biocompatibility in vitro and in vivo was done. The systematic study was performed providing consistent information which is important for further progress in cell growth and tissue engineering experiments. The chosen materials where of four different classes: well known biocompatible hybrid ORMOCER (Ormocore b59, Micro Resist) [1], widely used biodegradable di-acrylated poly(ethylene)glycol (PEG-DA-258, Sigma-Aldrich) [2], pure acrylate AKRE (SR368, Sartomer) [3] and novel high quality laser structurable material ORMOSIL (SZ2080, FORTH) [4]. All of the materials were evaluated by their suitability for femtosecond laser structuring, which is well established as a technique enabling rapid and flexible production of 3D micro/nanostructures. All photopolymers could be 3D structured with < 1 µm resolution and up to cm in overall sizes, thus materializing the computer models of the scaffolds with required pore sizes and porosities. The typical dimensions of scaffolds were 5 × 5 × 0.5 mm3 discs with 25 µm pore sizes and 40–60% porosity.
{"title":"Laser microstructured 3D polymeric biocompatible implants","authors":"M. Malinauskas, D. Baltriukienė, Antanas Kraniauskas, P. Danilevičius, E. Balčiūnas, A. Žukauskas, V. Purlys, R. Širmenis, V. Bukelskiene, R. Gadonas, V. Sirvydis, A. Piskarskas","doi":"10.1109/CLEOE.2011.5943232","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943232","url":null,"abstract":"In this report we present experimental results on biocompatibility based on stem cell growth experiments in vitro as well as reaction of living organism to polymer implants in vivo of femtosecond laser 3D micro/nanostructurable photopolymers. A synergetic study on materials for rapid 3D scaffold fabrication having micrometer features and being centimeter in size, their biocompatibility in vitro and in vivo was done. The systematic study was performed providing consistent information which is important for further progress in cell growth and tissue engineering experiments. The chosen materials where of four different classes: well known biocompatible hybrid ORMOCER (Ormocore b59, Micro Resist) [1], widely used biodegradable di-acrylated poly(ethylene)glycol (PEG-DA-258, Sigma-Aldrich) [2], pure acrylate AKRE (SR368, Sartomer) [3] and novel high quality laser structurable material ORMOSIL (SZ2080, FORTH) [4]. All of the materials were evaluated by their suitability for femtosecond laser structuring, which is well established as a technique enabling rapid and flexible production of 3D micro/nanostructures. All photopolymers could be 3D structured with < 1 µm resolution and up to cm in overall sizes, thus materializing the computer models of the scaffolds with required pore sizes and porosities. The typical dimensions of scaffolds were 5 × 5 × 0.5 mm3 discs with 25 µm pore sizes and 40–60% porosity.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85139359","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}
Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5942724
A. Canciamilla, F. Morichetti, N. Carlie, J. D. Musgraves, B. Zdyrko, I. Luzinov, K. Richardson, J. Hu, V. Singh, A. Agarwal, L. Kimerling, A. Melloni
Photosensitivity in chalcogenide glass waveguide allows for a permanent refractive index change by means of light exposure [1]. This property can be usefully exploited for post-fabrication trimming of integrated optical devices in order to compensate for fabrication imperfections and alleviate the need for restrictively tight fabrication tolerances [2]. In this work, visible light trimming is exploited to optimize the performance of coupled resonator filters realized by cascading micro-ring resonators in As2S3 glass technology.
{"title":"Visible light trimming of coupled ring-resonator filters in As2S3 chalcogenide glass technology","authors":"A. Canciamilla, F. Morichetti, N. Carlie, J. D. Musgraves, B. Zdyrko, I. Luzinov, K. Richardson, J. Hu, V. Singh, A. Agarwal, L. Kimerling, A. Melloni","doi":"10.1109/CLEOE.2011.5942724","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942724","url":null,"abstract":"Photosensitivity in chalcogenide glass waveguide allows for a permanent refractive index change by means of light exposure [1]. This property can be usefully exploited for post-fabrication trimming of integrated optical devices in order to compensate for fabrication imperfections and alleviate the need for restrictively tight fabrication tolerances [2]. In this work, visible light trimming is exploited to optimize the performance of coupled resonator filters realized by cascading micro-ring resonators in As2S3 glass technology.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85650097","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}
Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5942664
S. Bodrov, I. Ilyakov, B. Shishkin, A. Stepanov
Femtosecond laser pulses propagating in electro-optic crystal can generate wideband terahertz (THz) radiation via optical rectification. In the crystals with high optical nonlinearities and wide band gaps (small multiphoton absorption), such as LiNbO3 or LiTaO3, the optical group velocity is more than two times larger than the highest phase velocity of terahertz waves. To achieve phase-matching in such (superluminal) crystals the mechanism of Cherenkov radiation may be used. The main drawbacks of this method are typically strong terahertz absorption (∼ 20 cm−1 for LiNbO3) and diffraction of laser pump. To avoid these limitations it was proposed to use a planar sandwich structure with thin LiNbO3 core (to generate THz radiation and guide laser beam) and Si cladding (to output THz radiation with low absorption) [1]. This scheme showed experimentally the highest efficiency available today (∼ 0.1%) [2]. In further development of the scheme it was proposed to use a metal substrate to collect the terahertz emission into one direction and to control its spectrum by varying an air gap between the metal substrate and the LiNbO3 layer [3]. In this presentation we explore this scheme experimentally.
{"title":"Terahertz generation control by metal substrate in sandwich structure with thin LiNbO3","authors":"S. Bodrov, I. Ilyakov, B. Shishkin, A. Stepanov","doi":"10.1109/CLEOE.2011.5942664","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942664","url":null,"abstract":"Femtosecond laser pulses propagating in electro-optic crystal can generate wideband terahertz (THz) radiation via optical rectification. In the crystals with high optical nonlinearities and wide band gaps (small multiphoton absorption), such as LiNbO3 or LiTaO3, the optical group velocity is more than two times larger than the highest phase velocity of terahertz waves. To achieve phase-matching in such (superluminal) crystals the mechanism of Cherenkov radiation may be used. The main drawbacks of this method are typically strong terahertz absorption (∼ 20 cm−1 for LiNbO3) and diffraction of laser pump. To avoid these limitations it was proposed to use a planar sandwich structure with thin LiNbO3 core (to generate THz radiation and guide laser beam) and Si cladding (to output THz radiation with low absorption) [1]. This scheme showed experimentally the highest efficiency available today (∼ 0.1%) [2]. In further development of the scheme it was proposed to use a metal substrate to collect the terahertz emission into one direction and to control its spectrum by varying an air gap between the metal substrate and the LiNbO3 layer [3]. In this presentation we explore this scheme experimentally.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85885106","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}
Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5943696
J. Dobrindt, S. Karpf, S. Krysiak, B. Schroter, B. Nickel, J. Radler, T. Kippenberg
High-Q whispering gallery resonators, such as silica microspheres or microtoroids on a chip, have been successfully employed as optical biosensors [1]. Due to a high effective interaction length and a small mode volume, the resonance frequency is susceptible to small variations of the refractive index (RI). In particular, the observation of reactive wavelength shifts resulting from the adsorption of single virus has been reported [2].
{"title":"Dispersive single particle sensing with μs time resolution using toroidal microresonators","authors":"J. Dobrindt, S. Karpf, S. Krysiak, B. Schroter, B. Nickel, J. Radler, T. Kippenberg","doi":"10.1109/CLEOE.2011.5943696","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5943696","url":null,"abstract":"High-Q whispering gallery resonators, such as silica microspheres or microtoroids on a chip, have been successfully employed as optical biosensors [1]. Due to a high effective interaction length and a small mode volume, the resonance frequency is susceptible to small variations of the refractive index (RI). In particular, the observation of reactive wavelength shifts resulting from the adsorption of single virus has been reported [2].","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77146803","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}
Pub Date : 2011-05-22DOI: 10.1109/CLEOE.2011.5942484
A. Agnesi, F. Pirzio, G. Reali, Y.Z. Zhang, S. Veronesi, M. Tonelli
In the present work we report on the laser emission and spectroscopic investigation of a LuAG:Yb3+crystal, grown by micro-pulling down technique. In our knowledge the performances of the laser here reported are the best obtained for this grown technique. LuAG melts congruently around 2350 K and it has a cubic crystal structure [1], isomorphs to the most popular YAG. The relevance of this host relay on the almost constant thermal conductivity with the doping level, in contrast with the decreasing one of YAG. This feature makes LuAG an appealing material for high power laser applications opening the way to obtain low cost laser grade old and new materials. Low-power laser experiments in CW regime were performed in order to assess the crystal quality, employing several different output couplers in the range 0–30% in an X shaped cavity. The pump diode was a single-mode 300-mW laser diode (FLC GmbH), emitting at 935 nm with a narrow single-longitudinal and single-spatial mode with 50-pm linewidth. The Yb:LuAG laser crystal was a 4.5-mm long, 1%-doped rod, with a diameter of 3 mm. The active medium was contacted to a metallic plate, without any active cooling, and oriented at the Brewster angle in order to minimize insertion losses. The measured lifetime of the 2F5/2 manifold as 1030±20 µs at room temperature and the absorption coefficient was about 1.1 cm−1 at the pump wavelength.
{"title":"Laser performances and spectroscopic investigation of Yb:LuAG grown by µ-PD technique","authors":"A. Agnesi, F. Pirzio, G. Reali, Y.Z. Zhang, S. Veronesi, M. Tonelli","doi":"10.1109/CLEOE.2011.5942484","DOIUrl":"https://doi.org/10.1109/CLEOE.2011.5942484","url":null,"abstract":"In the present work we report on the laser emission and spectroscopic investigation of a LuAG:Yb3+crystal, grown by micro-pulling down technique. In our knowledge the performances of the laser here reported are the best obtained for this grown technique. LuAG melts congruently around 2350 K and it has a cubic crystal structure [1], isomorphs to the most popular YAG. The relevance of this host relay on the almost constant thermal conductivity with the doping level, in contrast with the decreasing one of YAG. This feature makes LuAG an appealing material for high power laser applications opening the way to obtain low cost laser grade old and new materials. Low-power laser experiments in CW regime were performed in order to assess the crystal quality, employing several different output couplers in the range 0–30% in an X shaped cavity. The pump diode was a single-mode 300-mW laser diode (FLC GmbH), emitting at 935 nm with a narrow single-longitudinal and single-spatial mode with 50-pm linewidth. The Yb:LuAG laser crystal was a 4.5-mm long, 1%-doped rod, with a diameter of 3 mm. The active medium was contacted to a metallic plate, without any active cooling, and oriented at the Brewster angle in order to minimize insertion losses. The measured lifetime of the 2F5/2 manifold as 1030±20 µs at room temperature and the absorption coefficient was about 1.1 cm−1 at the pump wavelength.","PeriodicalId":6331,"journal":{"name":"2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference (CLEO EUROPE/EQEC)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81125677","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：