High performance large aperture NIR single-mode VCSELs

Author(s):  
Martin Grabherr
2004 ◽  
Vol 19 (8) ◽  
pp. L86-L89 ◽  
Author(s):  
Fang-I Lai ◽  
Tao-Hung Hsueh ◽  
Ya-Hsien Chang ◽  
Hao-Chung Kuo ◽  
S C Wang ◽  
...  

2021 ◽  
Author(s):  
Minghong Xie ◽  
Wenxiao Gong ◽  
Lei Kong ◽  
Yang Liu ◽  
Yang Mi ◽  
...  

Abstract Perovskite nanocrystals (NCs) have emerged as attractive gain materials for solution-processed microlasers. Despite the recent surge of reports in this feld, it is still challenging to develop low-cost perovskite NCbased microlasers with high performance. Herein, we demonstrate low-threshold, spectrally tunable lasing from ensembles of CsPbBr3 NCs deposited on silica microspheres. Multiple whispering-gallery-mode lasing is achieved from individual NC/microspheres with a low threshold of ∼3.1 µJ cm−2 and cavity quality factor of ∼1193. Through time-resolved photoluminescence measurements, electron-hole plasma recombination is elucidated as the lasing mechanism. By tuning the microsphere diameter, the desirable single-mode lasing is successfully achieved. Remarkably, the CsPbBr3 NCs display durable room-temperature lasing under ∼107 shots of pulsed laser excitation, substantially exceeding the stability of conventional colloidal NCs. These CsPbBr3 NC-based microlasers can be potentially useful in photonic applications.


2011 ◽  
Vol 55-57 ◽  
pp. 1200-1205
Author(s):  
Liang Nie ◽  
Jun Han ◽  
Xu Jiang

The fiber point diffraction technology is applied in interferometer to measure optical surface with high precision. The wavefront diffracted from the single mode fiber with microns core diameter can be considered as ideal spherical wave and used as the referenced wave in interferometry. To estimate the quality of diffracted wavefront, the theoretical model of optical point diffraction is introduced at first. Based on the model, the influence of fiber core diameter, deformation and end-face shape on wavefront error is studied with numerical analysis. The analysis result shows that the single mode fiber used in experiment is available for instrument design and its influence over systematic error should be negligible within certain numerical aperture. Then a point diffraction interferometer with a single fiber is designed. Compared with the double fiber system, it has merit of noise immunity, high fringe contrast and high performance. Finally, the fiber point diffraction interferometer system is put up to measure spherical surface in experiment. The interference fringes are collected and analyzed with five-step shifting, least squares unwrapping and Zernike fitting method. The results show that the interferometer with optical fiber has achieved a worthy measurement precision and has great development potential.


Author(s):  
Hoda Sadeghian ◽  
Mehdi Tabe Arjmand ◽  
Hassan Salarieh ◽  
Aria Alasty

The taping mode Atomic Force Microscopic (T-AFM) can be properly described by a sinusoidal excitation of its base and nonlinear potential interaction with sample. Thus the cantilever may cause chaotic behavior which decreases the performance of the sample topography. In this paper a nonlinear delayed feedback control is proposed to control chaos in a single mode approximation of a T-AFM system. Assuming model parameters uncertainties, the first order Unstable Periodic Orbits (UPOs) of the system is stabilized using the sliding nonlinear delayed feedback control. The effectiveness of the presented methods is numerically verified and the results show the high performance of the controller.


2015 ◽  
Author(s):  
Christopher N. Pannell ◽  
Jon D. Ward ◽  
Elliot S. Wachman ◽  
Bill G. Zhang ◽  
Murray K. Reed

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