Pulsed-Pump Laser-Induced Transition in Chalcogenide GST for Hybrid Plasmonic Modulator Application

Using a fiber of that is 125 μm in diameter in rhodamine 6G ethanol solution, controllable multi- and single-whispering-gallery-mode (WGM) optofluidic lasers based on evanescent-wave-coupled gain are both available. With multi-mode WGM emission, lasing emission with almost pure TM (transverse magnetic) or almost TE (transverse electric) modes can be obtained when the pump laser has an electric field parallel (perpendicular) to the fiber axis, i.e., the polarization direction of output laser is the same as that of the pump laser. On the other hand, when the laser emission is single-mode, the TE output laser always emerges firstly above lasing threshold, then keeps TE mode while the pump laser’s intensity increases with polarization direction perpendicular to the fiber axis; on the contrary, TE emission will dwindle relatively, while the TM emission emerges and dominates the spectra, when the pump laser’s intensity increases with polarization parallel to the fiber axis. Our work proves that controlling the leakage of the evanescent wave from high-Q microcavities is crucial for both modes of lasing emission and its polarization.

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A Temoo FIR Laser with Integrated Pump Laser

1979 International Conference on Submillimeter Waves and Their Applications ◽

10.1109/icswa.1979.9335350 ◽

1979 ◽

Author(s):

M. Tacke ◽

P. Dyrna

Keyword(s):

Pump Laser ◽

Fir Laser

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A method for studying pico to microsecond time-resolved core-level spectroscopy used to investigate electron dynamics in quantum dots

Scientific Reports ◽

10.1038/s41598-020-79792-z ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Tamara Sloboda ◽

Sebastian Svanström ◽

Fredrik O. L. Johansson ◽

Aneta Andruszkiewicz ◽

Xiaoliang Zhang ◽

...

Keyword(s):

Quantum Dots ◽

Electron Injection ◽

Core Level ◽

Pump Laser ◽

Repetition Frequency ◽

Specific Information ◽

Single Experiment ◽

Time Resolved ◽

X Ray ◽

Pbs Quantum Dots

AbstractTime-resolved photoelectron spectroscopy can give insights into carrier dynamics and offers the possibility of element and site-specific information through the measurements of core levels. In this paper, we demonstrate that this method can access electrons dynamics in PbS quantum dots over a wide time window spanning from pico- to microseconds in a single experiment carried out at the synchrotron facility BESSY II. The method is sensitive to small changes in core level positions. Fast measurements at low pump fluences are enabled by the use of a pump laser at a lower repetition frequency than the repetition frequency of the X-ray pulses used to probe the core level electrons: Through the use of a time-resolved spectrometer, time-dependent analysis of data from all synchrotron pulses is possible. Furthermore, by picosecond control of the pump laser arrival at the sample relative to the X-ray pulses, a time-resolution limited only by the length of the X-ray pulses is achieved. Using this method, we studied the charge dynamics in thin film samples of PbS quantum dots on n-type MgZnO substrates through time-resolved measurements of the Pb 5d core level. We found a time-resolved core level shift, which we could assign to electron injection and charge accumulation at the MgZnO/PbS quantum dots interface. This assignment was confirmed through the measurement of PbS films with different thicknesses. Our results therefore give insight into the magnitude of the photovoltage generated specifically at the MgZnO/PbS interface and into the timescale of charge transport and electron injection, as well as into the timescale of charge recombination at this interface. It is a unique feature of our method that the timescale of both these processes can be accessed in a single experiment and investigated for a specific interface.

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Pump Laser Automatic Signal Control for Erbium-Doped Fiber Amplifier Gain, Noise Figure, and Output Spectral Power

Journal of Optical Communications ◽

10.1515/joc-2019-0203 ◽

2019 ◽

Vol 0 (0) ◽

Author(s):

I. S. Amiri ◽

Ahmed Nabih Zaki Rashed ◽

P. Yupapin

Keyword(s):

Noise Figure ◽

Spectral Power ◽

Power Level ◽

Fiber Amplifier ◽

Pump Laser ◽

Output Power Level ◽

Signal Control ◽

Erbium Doped Fiber Amplifier ◽

Erbium Doped ◽

Amplifier Gain

AbstractThis paper has simulated the pump laser automatic signal control for erbium-doped fiber amplifier gain, noise figure, and output spectral power. Signal gain and noise figure are deeply studied in relation to laser pump power variations at operating pumping wavelengths of 980 nm and 1,480 nm for previous and proposed models. Similar to the study of the light signal to noise ratio, output power level and maximum Q factor are also simulated versus EDFA amplifier length at pumping power of 500 mW and different pumping wavelength by using the proposed model. The obtained results are better by using a pumping wavelength of 1,480 nm than a pumping wavelength of 980 nm. The optimum EDFA amplifier is 5 m, which gives better performance than other amplifier lengths.

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Influence of spectrum characteristics on the output efficiency of LED pump laser

Optik ◽

10.1016/j.ijleo.2021.167561 ◽

2021 ◽

pp. 167561

Author(s):

Wendi Huang ◽

Tianzhuo Zhao ◽

Hong Xiao ◽

Shenghai Zhao ◽

Shuzhen Nie ◽

...

Keyword(s):

Pump Laser ◽

Output Efficiency ◽

Spectrum Characteristics

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Carbon Overcoat Loss From the Surface of a Heat Assisted Magnetic Storage Disk due to Laser Irradiation

ASME 2013 Conference on Information Storage and Processing Systems ◽

10.1115/isps2013-2947 ◽

2013 ◽

Cited By ~ 3

Author(s):

Paul M. Jones ◽

Joachim Ahner ◽

Christopher L. Platt ◽

Huan Tang ◽

Julius Hohlfeld

Keyword(s):

Curie Temperature ◽

Laser Power ◽

Single Point ◽

Magnetic Layer ◽

Pump Laser ◽

Probe Laser ◽

Magnetic Storage ◽

Carbon Overcoat ◽

Fept Alloy ◽

The Media

A pump-probe experimental technique that incorporated a 527nm wavelength pump laser and a 476nm probe laser was applied to a magnetic storage disk having a magnetic layer comprised of a FePt alloy and coated with a hydrogenated carbon overcoat (COC). The pump laser power was systematically increased while sweeping the applied field with an electromagnet to observe the temperature dependent magnetization, which is proportional to the change in the polarization of the reflected beam. In this way the laser power required to heat the media to the Curie temperature (Tc) was determined, with the Curie temperature of the media determined from a separate magnetometry measurement. Such a single point laser power-to-media temperature calibration allowed the determination of the media temperature over a small laser power range near Tc. The carbon over-coated FePt media was then irradiated for varying durations at temperatures pertinent to a Heat Assisted Magnetic Recording (HAMR) device [1]. The COC surface topography and carbon bonding structure within each irradiated zone was probed with AFM and micro-spot Raman. A subtle, systematic temperature and duration dependent change in the COC was observed. With increasing temperature and duration, the Raman D-peak became increasingly pronounced, signaling an increase of the sp2 (disorder) content in the film in the irradiated region. At incrementally higher temperatures, the loss of the carbon overcoat becomes apparent as a shallow depression in the COC film in the irradiated area. A clearer picture of the possible sensitivity and kinetics of the loss of COC on the HAMR media surface was obtained by measuring its loss over a range of irradiation temperatures and durations. The activation energy and COC loss rate were obtained and a possible mechanism for COC failure-loss was discussed within the bounds of the operating HAMR device [2].

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