The Experts below are selected from a list of 180 Experts worldwide ranked by ideXlab platform

Umit Demirbas - One of the best experts on this subject based on the ideXlab platform.

  • widely tunable dual wavelength tm ylf tm luag and tm yag lasers
    European Quantum Electronics Conference, 2019
    Co-Authors: Ersen Beyatli, Umit Demirbas
    Abstract:

    Dual-wavelength operation of lasers are attractive for many applications such as coherent terahertz wave generation, ultrahigh pulse repetition rate creation by optical beating, and laser ranging. Several methods could be employed for achieving multicolor laser operation including usage of specially coated cavity optics, employment of dual laser crystals, utilization of coupled cavities, and deployment of Fabry-Perot band-pass Filters or volume Bragg gratings. Most of the time, these approaches provide multicolor laser operation at a single wavelength pair, and laser power in each line might fluctuate with experimental conditions (such as crystal temperature and pump power variations). In recent years, usage of intracavity Birefringent Filters (BRFs) was proposed as a flexible method for the generation of multicolor laser operation [1–4]. Advantages of BRFs in multicolor lasing include: (a) low cost, (b) simple operation, (c) one BRF plate empowering multicolor laser operation in many different wavelength pairs, (d) capability to control laser power in each line, (e) ability to use a rich number of filter parameters from a single BRF plate, (f) effectiveness in continuous-wave, gain-switched, Q-switched and cw mode-locked regimes, and (g) universal usage of the device in any laser that lies within the transmission bandwidth of the BRF plate. In our earlier work, we have employed a 3-mm thick, off-surface optic axis crystalline quartz BRF with an optic axis 45° to the surface of the plate to generate two-color cw laser operation in 11 and 10 different transition combinations in Cr:Nd:GSGG and Cr:LiSAF [3], respectively. In this study [5], we have demonstrated that the same BRF plate could also be used for multicolor laser operation of solid-state lasers around 2 μm. Optimization of the rotation angle of the intracavity inserted BRF plate around different orders (rotation angles) facilitated two-color laser operation in 11, 12 and 8 different wavelength pairs in Tm:YLF, Tm:LuAG and Tm:YAG, respectively [5]. For most of the cases, fine tuning of the BRF rotation angle enabled adjustment of laser power in each line. Figure 1 (a) shows sample optical spectra for Tm:YLF, and Fig. 1 (b) demonstrates details of cavity dynamics for synchronous dual-wavelength operation of Tm:YLF at 1868 & 1991 nm pair. To our knowledge, this is the first report of multicolor laser operation in Tm:LuAG and Tm:YAG, and first results with a BRF in Tm:YLF [6]. Moreover, the demonstrated wide-tunability of two-color laser wavelengths is quite rare in literature.

  • widely tunable dual wavelength operation of tm ylf tm luag and tm yag lasers using off surface optic axis Birefringent Filters
    Applied Optics, 2018
    Co-Authors: Ersen Beyatli, Umit Demirbas
    Abstract:

    : In this work, we have demonstrated dual-wavelength continuous-wave laser operation in diode-end-pumped Tm:YLF, Tm:LuAG, and Tm:YAG lasers. A 3-mm-thick quartz Birefringent filter with an optical axis 45° to the surface plane was exploited for achieving broadly tunable two-color laser operation. By using the different orders of the filter with varying filter width and free spectral range values, dual-wavelength operation has been achieved in 11, 12, and 8 different wavelength pairs in Tm:YLF, Tm:LuAG, and Tm:YAG, respectively. Fine tuning of the rotation angle of the Birefringent filter enabled control of laser power in each line. To our knowledge, this is the first report of multicolor laser operation in these gain media, and the technique used is applicable to other laser operation regimes including mode-locking.

  • Off-surface optic axis Birefringent Filters for smooth tuning of broadband lasers
    Applied optics, 2017
    Co-Authors: Umit Demirbas
    Abstract:

    Transition metal-doped gain media, such as Ce:LiCAF, Ti:sapphire, Cr:ZnSe, and Fe:ZnSe, possess wide gain bandwidths that could provide ultra broadly tunable laser output with the usage of adequate intracavity tuning elements. Birefringent Filters (BRFs) are a low-cost and easy to use solution for tuning. However, for ultrabroad gain media, regular on-surface optic axis BRFs could not provide smooth tuning of laser wavelength in the whole emission range. Basically, regular BRFs could not accommodate a large enough free spectral range with acceptable modulation depth variation while tuning, due to their slow tuning rates. Motivated by this, in this study, we have numerically investigated the effect of optic axis orientation on filter parameters for magnesium fluoride Birefringent tuning plates. We have shown that a magnesium fluoride BRF with an optic axis diving by 30° into the plate could provide smooth tuning of ultra-broad laser gain media. A similar analysis has shown that for broadband tuning applications, the optimum optic axis diving angle lies around 25° for crystal quartz BRFs. The proposed Filters have the potential to be useful in tuning of broadband lasers in continuous-wave, long-pulsed, and femtosecond operation regimes.

  • Multicolor lasers using Birefringent Filters: experimental demonstration with Cr:Nd:GSGG and Cr:LiSAF
    Optics express, 2017
    Co-Authors: Umit Demirbas, Reinhard Uecker, James G. Fujimoto, Alfred Leitenstorfer
    Abstract:

    In this study, we numerically and experimentally investigate application of Birefringent Filters (BRFs) as frequency selective elements in multicolor lasers. A BRF plate made out of crystalline quartz with an arbitrarily oriented optical axis has been explored. Simulation results have shown that compared to regular BRFs where the optical axis lies in the plane of the plates surface, a BRF with an optical axis pointing out of its surface enables design flexibility in filter parameters, providing access to a wider set of free spectral range and bandwidth values. As a result, multicolor operation could be obtained in many wavelength pairs using a single BRF plate. In the experiments a 3-mm thick quartz BRF with an optical axis 45° to the surface plane has been used. With Cr:Nd:GSGG as a laser medium two-color and three-color cw laser operation has been demonstrated in 11 and 3 different transition combinations, respectively. Moreover, two-color laser operation has been demonstrated in 10 different wavelength pairs in Cr:LiSAF. To our knowledge, this study is the first detailed investigation and experimental demonstration of BRFs with tilted optical axis for multicolor operation of solid-state lasers. Compared to other methods, BRFs enable a rich selection of transition pairs and also the ratio of the power in each line could be regulated by fine adjustment of the rotation angle. Implementation of tilted-axis BRFs should boost development of efficient and low-cost multicolor lasers in other gain media as well.

  • multicolor lasers employing Birefringent Filters with an arbitrarily oriented optical axis
    European Quantum Electronics Conference, 2017
    Co-Authors: Umit Demirbas, James G. Fujimoto, P Reiche, Alfred Leitenstorfer
    Abstract:

    Dual-wavelength and tri-wavelength operation of solid-state lasers has been attracting a great deal of attention, due to the need for such sources in applications like coherent terahertz generation [1]. Multicolor laser operation has been shown in many solid-state laser gain media including Nd:YAG, Yb:KGW, Tm:YAP, Cr:LiSAF, Alexandrite, Tm:CaYAlO4, and Ti:Sapphire. Most of the earlier studies report dual/triple wavelength operation in a few pairs of lines. Furthermore, the ratio of the power in each line varies with external factors such as pump power, and could not be controlled easily. These disadvantages are due to the method used for frequency selection, where operating in a multi-wavelength regime requires specially coated cavity optics and/or coupled cavities, which can usually be optimized for a single transition pair at a fixed output coupling and pump power.

Mahmoud Fallahi - One of the best experts on this subject based on the ideXlab platform.

  • high power two color orbital angular momentum beam generation using vertical external cavity surface emitting lasers
    Applied Physics Letters, 2018
    Co-Authors: Michal Lukowski, Chris Hessenius, Jason T Meyer, Ewan M Wright, Mahmoud Fallahi
    Abstract:

    We report the design and experimental results for a two-chip T-cavity vertical external cavity surface emitting laser utilized for two-color collinear generation of Hermite-Gaussian and Laguerre-Gaussian (LG) transverse modes. A combination of intracavity mode-control elements and an external astigmatic mode converter was used to achieve high power LG modes. By incorporating intracavity Birefringent Filters in each arm of the T-cavity, wide wavelength tuning in excess of 12 nm of each mode is demonstrated. Output power exceeding 1.5 W is measured for all the modes.

Michal Lukowski - One of the best experts on this subject based on the ideXlab platform.

  • high power two color orbital angular momentum beam generation using vertical external cavity surface emitting lasers
    Applied Physics Letters, 2018
    Co-Authors: Michal Lukowski, Chris Hessenius, Jason T Meyer, Ewan M Wright, Mahmoud Fallahi
    Abstract:

    We report the design and experimental results for a two-chip T-cavity vertical external cavity surface emitting laser utilized for two-color collinear generation of Hermite-Gaussian and Laguerre-Gaussian (LG) transverse modes. A combination of intracavity mode-control elements and an external astigmatic mode converter was used to achieve high power LG modes. By incorporating intracavity Birefringent Filters in each arm of the T-cavity, wide wavelength tuning in excess of 12 nm of each mode is demonstrated. Output power exceeding 1.5 W is measured for all the modes.

Ersen Beyatli - One of the best experts on this subject based on the ideXlab platform.

  • widely tunable dual wavelength tm ylf tm luag and tm yag lasers
    European Quantum Electronics Conference, 2019
    Co-Authors: Ersen Beyatli, Umit Demirbas
    Abstract:

    Dual-wavelength operation of lasers are attractive for many applications such as coherent terahertz wave generation, ultrahigh pulse repetition rate creation by optical beating, and laser ranging. Several methods could be employed for achieving multicolor laser operation including usage of specially coated cavity optics, employment of dual laser crystals, utilization of coupled cavities, and deployment of Fabry-Perot band-pass Filters or volume Bragg gratings. Most of the time, these approaches provide multicolor laser operation at a single wavelength pair, and laser power in each line might fluctuate with experimental conditions (such as crystal temperature and pump power variations). In recent years, usage of intracavity Birefringent Filters (BRFs) was proposed as a flexible method for the generation of multicolor laser operation [1–4]. Advantages of BRFs in multicolor lasing include: (a) low cost, (b) simple operation, (c) one BRF plate empowering multicolor laser operation in many different wavelength pairs, (d) capability to control laser power in each line, (e) ability to use a rich number of filter parameters from a single BRF plate, (f) effectiveness in continuous-wave, gain-switched, Q-switched and cw mode-locked regimes, and (g) universal usage of the device in any laser that lies within the transmission bandwidth of the BRF plate. In our earlier work, we have employed a 3-mm thick, off-surface optic axis crystalline quartz BRF with an optic axis 45° to the surface of the plate to generate two-color cw laser operation in 11 and 10 different transition combinations in Cr:Nd:GSGG and Cr:LiSAF [3], respectively. In this study [5], we have demonstrated that the same BRF plate could also be used for multicolor laser operation of solid-state lasers around 2 μm. Optimization of the rotation angle of the intracavity inserted BRF plate around different orders (rotation angles) facilitated two-color laser operation in 11, 12 and 8 different wavelength pairs in Tm:YLF, Tm:LuAG and Tm:YAG, respectively [5]. For most of the cases, fine tuning of the BRF rotation angle enabled adjustment of laser power in each line. Figure 1 (a) shows sample optical spectra for Tm:YLF, and Fig. 1 (b) demonstrates details of cavity dynamics for synchronous dual-wavelength operation of Tm:YLF at 1868 & 1991 nm pair. To our knowledge, this is the first report of multicolor laser operation in Tm:LuAG and Tm:YAG, and first results with a BRF in Tm:YLF [6]. Moreover, the demonstrated wide-tunability of two-color laser wavelengths is quite rare in literature.

  • widely tunable dual wavelength operation of tm ylf tm luag and tm yag lasers using off surface optic axis Birefringent Filters
    Applied Optics, 2018
    Co-Authors: Ersen Beyatli, Umit Demirbas
    Abstract:

    : In this work, we have demonstrated dual-wavelength continuous-wave laser operation in diode-end-pumped Tm:YLF, Tm:LuAG, and Tm:YAG lasers. A 3-mm-thick quartz Birefringent filter with an optical axis 45° to the surface plane was exploited for achieving broadly tunable two-color laser operation. By using the different orders of the filter with varying filter width and free spectral range values, dual-wavelength operation has been achieved in 11, 12, and 8 different wavelength pairs in Tm:YLF, Tm:LuAG, and Tm:YAG, respectively. Fine tuning of the rotation angle of the Birefringent filter enabled control of laser power in each line. To our knowledge, this is the first report of multicolor laser operation in these gain media, and the technique used is applicable to other laser operation regimes including mode-locking.

Alfred Leitenstorfer - One of the best experts on this subject based on the ideXlab platform.

  • Multicolor lasers using Birefringent Filters: experimental demonstration with Cr:Nd:GSGG and Cr:LiSAF
    Optics express, 2017
    Co-Authors: Umit Demirbas, Reinhard Uecker, James G. Fujimoto, Alfred Leitenstorfer
    Abstract:

    In this study, we numerically and experimentally investigate application of Birefringent Filters (BRFs) as frequency selective elements in multicolor lasers. A BRF plate made out of crystalline quartz with an arbitrarily oriented optical axis has been explored. Simulation results have shown that compared to regular BRFs where the optical axis lies in the plane of the plates surface, a BRF with an optical axis pointing out of its surface enables design flexibility in filter parameters, providing access to a wider set of free spectral range and bandwidth values. As a result, multicolor operation could be obtained in many wavelength pairs using a single BRF plate. In the experiments a 3-mm thick quartz BRF with an optical axis 45° to the surface plane has been used. With Cr:Nd:GSGG as a laser medium two-color and three-color cw laser operation has been demonstrated in 11 and 3 different transition combinations, respectively. Moreover, two-color laser operation has been demonstrated in 10 different wavelength pairs in Cr:LiSAF. To our knowledge, this study is the first detailed investigation and experimental demonstration of BRFs with tilted optical axis for multicolor operation of solid-state lasers. Compared to other methods, BRFs enable a rich selection of transition pairs and also the ratio of the power in each line could be regulated by fine adjustment of the rotation angle. Implementation of tilted-axis BRFs should boost development of efficient and low-cost multicolor lasers in other gain media as well.

  • multicolor lasers employing Birefringent Filters with an arbitrarily oriented optical axis
    European Quantum Electronics Conference, 2017
    Co-Authors: Umit Demirbas, James G. Fujimoto, P Reiche, Alfred Leitenstorfer
    Abstract:

    Dual-wavelength and tri-wavelength operation of solid-state lasers has been attracting a great deal of attention, due to the need for such sources in applications like coherent terahertz generation [1]. Multicolor laser operation has been shown in many solid-state laser gain media including Nd:YAG, Yb:KGW, Tm:YAP, Cr:LiSAF, Alexandrite, Tm:CaYAlO4, and Ti:Sapphire. Most of the earlier studies report dual/triple wavelength operation in a few pairs of lines. Furthermore, the ratio of the power in each line varies with external factors such as pump power, and could not be controlled easily. These disadvantages are due to the method used for frequency selection, where operating in a multi-wavelength regime requires specially coated cavity optics and/or coupled cavities, which can usually be optimized for a single transition pair at a fixed output coupling and pump power.