scholarly journals Unusual Polarization Relation between Single-Mode Lasing Emission and Excitation Laser from an Evanescent-Wave Pumped Micro-Cavity Laser

Photonics ◽  
2021 ◽  
Vol 8 (3) ◽  
pp. 66
Author(s):  
Yuchen Wang ◽  
Hongsheng Li ◽  
Shu Hu ◽  
Heng Li ◽  
Chuanxiang Sheng
Keyword(s):  
Evanescent Wave ◽  
Single Mode ◽  
Transverse Magnetic ◽  
Ethanol Solution ◽  
Pump Laser ◽  
Fiber Axis ◽  
Lasing Threshold ◽  
Polarization Direction ◽  
Excitation Laser ◽  
Output Laser

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.

scholarly journals Controllable Polarization of Lasing Emission From a Polymer Microfiber Laser

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Van Duong Ta ◽  
Rui Chen ◽  
Handong Sun
Keyword(s):  
Optical Sensors ◽  
Transverse Magnetic ◽  
Optical Switches ◽  
Pulse Excitation ◽  
Whispering Gallery ◽  
Low Threshold ◽  
Output Laser ◽  
On Chip ◽  
Doped Polymer ◽  
Lasing Modes

AbstractMicrolasers with controllable polarization of output emission are vital for on-chip optical communications, optical sensors and optical switches. In this work, we report a high quality (Q) factor, low-threshold polymer microfiber laser and the possibility of achieving laser emission with a desired polarization. The microfiber is fabricated by direct drawing from a dye-doped polymer solution and it can generate whispering gallery mode (WGM) lasing under optical pulse excitation. When the microfiber is pumped from the side with pumping direction perpendicular to the microfiber’s axis, the polarization direction of the output laser is found to be the same as that of the pump laser. Lasing emission with either transverse electric (TE) or transverse magnetic (TM) modes can be obtained and these two polarization states can be switched over by tuning the pumping laser. Furthermore, emission with both TE and TM modes can also be observed by changing the orientation of the microfiber relatively to pumping direction. Our finding provides an effective approach for achieving microlasers that have high Q lasing modes with anticipated polarization.

Characterization of single-mode coated fibers at low temperatures using periodic distortion of the fiber axis

1987 ◽  
Vol 5 (8) ◽  
pp. 1111-1117
Author(s):  
H. Grebel ◽  
G. Herskowitz ◽  
M. Mezhoudi
Keyword(s):  
Low Temperatures ◽  
Single Mode ◽  
Fiber Axis

Reversible All-Optical Modulation Based on Evanescent Wave Absorption of a Single-Mode Fiber With Azo-Polymer Overlay

2010 ◽  
Vol 22 (18) ◽  
pp. 1352-1354 ◽  
Author(s):  
Xiujie Tian ◽  
Xusheng Cheng ◽  
Wenxuan Wu ◽  
Yanhua Luo ◽  
Qijin Zhang ◽  
...  
Keyword(s):  
Evanescent Wave ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Optical Modulation ◽  
Wave Absorption ◽  
Azo Polymer ◽  
All Optical

scholarly journals Fluorescence and Time-Delayed Lasing during Single Laser Pulse Excitation of a Pendant mm-Sized Dye Droplet

Molecules ◽  
2019 ◽  
Vol 24 (24) ◽  
pp. 4464 ◽  
Author(s):  
Mihai Boni ◽  
Ionut Relu Andrei ◽  
Mihail Lucian Pascu ◽  
Angela Staicu
Keyword(s):  
Laser Pulse ◽  
Fluorescence Emission ◽  
Emission Spectra ◽  
Lasing Threshold ◽  
Pulse Excitation ◽  
Signal Acquisition ◽  
Time Shape ◽  
Excitation Laser ◽  
Excitation Laser Pulse ◽  
Laser Pulse Intensity

Fluorescence and lasing emission that are produced separately in time during excitation laser pulse for an mm-sized Rhodamine 6G dye-water droplet are reported. The droplet acts as a quasi-spherical closed optical resonator and due to multiple internal reflections, the resonant amplified emission is delayed with respect to fluorescence emission. Measurements of the temporal evolution of the droplet’s emission were performed by varying the signal acquisition gate width and gate delay with respect to the pumping pulse. The droplet emission spectra are structured in two bands which appear one after the other in time: first, the fluorescence emission band which follows pumping laser pulse time shape and then a second band, the lasing band, placed at shorter wavelengths and formed in time after the peak of the pumping laser pulse intensity, on the pulse tail. The lasing threshold pumping intensity is much lower than those for typical dye lasers.

Photonic Crystal Fiber Sensor for Blood with Different Concentration of Zinc

2020 ◽  
Vol 1002 ◽  
pp. 290-299
Author(s):  
Raghad Hani ◽  
Bushra R. Mahdi ◽  
Ayad Z. Mohammad
Keyword(s):  
Photonic Crystal ◽  
Photonic Crystal Fiber ◽  
Optical Fibers ◽  
Human Blood ◽  
Zinc Concentration ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Concentration Change ◽  
Crystal Fiber ◽  
Output Laser

Zinc is one of the important material in human blood because of its effect in defensive system work for properly and it plays an important role in growth, wound healing Medically zinc concentration effect directly in skin health so it's important to make a sensor for discover zinc and its concentration change in human blood for each of male and female. Optical fibers are used as a sensor for detecting zinc and its concentration by transmitted laser signal through the optical fiber by using different types (single mode fiber SMF, photonic crystal fiber PCF) by studying the results of output laser the detection can be seen for zinc concentration change, the design of small PCF which the same LMA_10 but smaller in its radius of core and cladding even the distance between cores. The smallest PCF size has the best detection for all zinc concentration change in blood all that was done by comsol Multiphysics 5.4 simulation program

Single Mode Wave Guide with a Liquid Crystalline Core

1997 ◽  
Vol 06 (01) ◽  
pp. 81-93 ◽  
Author(s):  
J. A. Reyes ◽  
R. F. Rodriguez
Keyword(s):  
Spatial Distribution ◽  
Liquid Crystalline ◽  
Single Mode ◽  
Transverse Magnetic ◽  
Optical Field ◽  
Waveguide Effect ◽  
Crystalline Core ◽  
Waveguide Model ◽  
Optical Limit ◽  
Ray Trajectories

A model for a planar single mode waveguide with a thermotropic nematic core is discussed. In previous work we have shown that in the optical limit this guide is multimodal and that a waveguide effect exists and concentrates the ray trajectories in the central part of the cell. In this work we show that for the WKB limit the same waveguide model may become single modal. To derive the conditions under which this regime may be attained, we first calculate the propagating transverse magnetic (TM) modes, their cut off frequency and the maximum number of modes for a given frequency of the incident optical field. From these results we then derive the condition to have a unimodal waveguide and calculate the spatial distribution of the electromagnetic energy density within the cell. We show that the waveguide effect may still exist for the strong regime only, by exhibiting that this energy is concentrated between two caustics in the central part of the cell. Finally, we discuss the limitations and possible generalizations of our model and give some concluding remarks.

scholarly journals Miniature on-fiber extrinsic Fabry-Perot interferometric vibration sensors based on micro-cantilever beam

2019 ◽  
Vol 8 (1) ◽  
pp. 293-298 ◽  
Author(s):  
Weiyi Ma ◽  
Yi Jiang ◽  
Han Zhang ◽  
Liuchao Zhang ◽  
Jie Hu ◽  
...  
Keyword(s):  
Cantilever Beam ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Vibration Sensor ◽  
Fiber Axis ◽  
Vibration Sensors ◽  
Beam Design ◽  
Cantilever Length ◽  
Fabry Perot ◽  
Micro Cantilever

Abstract An on-fiber extrinsic Fabry–Perot interferometric (EFPI) vibration sensor based on micro-cantilever beam is proposed and experimentally demonstrated. The micro-cantilever beam, with a cantilever length of 80μm and a cantilever thickness of 5μm, is created perpendicular to the fiber axis by using the femtosecond laser micro-machining technique. The on-fiber vibration sensor has same diameter with that of the single mode fiber. An acceleration sensitivity of 11.1 mV/g@300 Hz in the range of 0.5-5g is demonstrated experimentally. This on-fiber and micro-cantilever beam design allows for the sensor to be smaller size and higher temperature resistance.

Growth and Stabilization of Hot Spots in Microwave Heated Ceramic Fibers

1994 ◽  
Vol 347 ◽  
Author(s):  
Gregory A. Kriegsmann
Keyword(s):  
Electric Field ◽  
Hot Spots ◽  
Hot Spot ◽  
Single Mode ◽  
Uniform Electric Field ◽  
Fiber Axis ◽  
Ceramic Fibers ◽  
Mathematical Equations ◽  
Effective Heat Transfer Coefficient ◽  
Ceramic Cylinder

ABSTRACTRecently the heating of a thin ceramic cylinder in a single mode applicator was modeled and analyzed assuming a small Biot number and a known uniform electric field through out the sample. The resulting simplified mathematical equations explained the mechanism for the generation and growth of localized regions of high temperature. The results predicted that a hot-spot, once formed, will grow until it consumes the entire sample. Although this phenomenon is seen in some experiments, others show that the hot-spot stabilizes and moves no further.A new model is proposed which incorporates the dependence of the thermal conductivity and the effective heat transfer coefficient upon temperature, and the nonuniformity of the electric field along the fiber axis. The resulting simplified mathematical equations indicate that these effects may stabilize the growth of hot-spots.

1.02-μm pump laser diodes with high power above 300 mW into single mode fiber

1995 ◽  
Author(s):  
Mitsuru Sugo ◽  
Jiro Temmyo ◽  
Teruhiko Nishiya ◽  
Eiichi Kuramochi ◽  
Toshiaki Tamamura
Keyword(s):  
High Power ◽  
Laser Diodes ◽  
Single Mode ◽  
Single Mode Fiber ◽  
Pump Laser
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