scholarly journals Spin-VCSELs with Local Optical Anisotropies: Toward Terahertz Polarization Modulation

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
M. Drong ◽  
T. Fördös ◽  
H.Y. Jaffrès ◽  
J. Peřina ◽  
K. Postava ◽  
...  
Keyword(s):  
Polarization Modulation

scholarly journals Neuro-Inspired Computing with Spin-VCSELs

2021 ◽  
Vol 11 (9) ◽  
pp. 4232
Author(s):  
Krishan Harkhoe ◽  
Guy Verschaffelt ◽  
Guy Van der Sande
Keyword(s):  
Processing Speed ◽  
Delay Time ◽  
High Speed ◽  
State Of The Art ◽  
Polarization Modulation ◽  
Time Interval ◽  
Computing Technique ◽  
High Modulation ◽  
Short Time ◽  
Modulation Speed

Delay-based reservoir computing (RC), a neuromorphic computing technique, has gathered lots of interest, as it promises compact and high-speed RC implementations. To further boost the computing speeds, we introduce and study an RC setup based on spin-VCSELs, thereby exploiting the high polarization modulation speed inherent to these lasers. Based on numerical simulations, we benchmarked this setup against state-of-the-art delay-based RC systems and its parameter space was analyzed for optimal performance. The high modulation speed enabled us to have more virtual nodes in a shorter time interval. However, we found that at these short time scales, the delay time and feedback rate heavily influence the nonlinear dynamics. Therefore, and contrary to other laser-based RC systems, the delay time has to be optimized in order to obtain good RC performances. We achieved state-of-the-art performances on a benchmark timeseries prediction task. This spin-VCSEL-based RC system shows a ten-fold improvement in processing speed, which can further be enhanced in a straightforward way by increasing the birefringence of the VCSEL chip.

scholarly journals Spin Laser Local Oscillators for Homodyne Detection in Coherent Optical Communications

Micromachines ◽  
2021 ◽  
Vol 12 (5) ◽  
pp. 573
Author(s):  
Nobuhide Yokota ◽  
Hiroshi Yasaka
Keyword(s):  
Spin Polarization ◽  
Optical Communications ◽  
Injection Locking ◽  
Optical Data ◽  
Cavity Surface ◽  
Orthogonal Polarization ◽  
Linear Birefringence ◽  
Polarization Modulation ◽  
Homodyne Detection ◽  
Local Oscillators

We numerically investigate spin-controlled vertical-cavity surface-emitting lasers (spin-VCSELs) for local oscillators, which are based on an injection locking technique used in coherent optical communications. Under the spin polarization modulation of an injection-locked spin-VCSEL, frequency-shifted and phase-correlated optical sidebands are generated with an orthogonal polarization against the injection light, and one of the sidebands is resonantly enhanced due to the linear birefringence in the spin-VCSEL. We determine that the peak strength and peak frequency in the spin polarization modulation sensitivity of the injection-locked spin-VCSEL depend on detuning frequency and injection ratio conditions. As a proof of concept, 25-Gbaud and 16-ary quadrature amplitude modulation optical data signals and a pilot tone are generated, and the pilot tone is used for the injection locking of a spin-VCSEL. An orthogonally-polarized modulation sideband generated from the injection-locked spin-VCSEL is used as a frequency-shifted local oscillator (LO). We verify that the frequency-shifted LO can be used for the homodyne detection of optical data signals with no degradation. Our findings suggest a novel application of spin-VCSELs for coherent optical communications.

scholarly journals Optimal polarization modulation for orthogonal two-axis Lloyd’s mirror interference lithography

2017 ◽  
Vol 25 (19) ◽  
pp. 22237 ◽  
Author(s):  
Xiuguo Chen ◽  
Zongwei Ren ◽  
Yuki Shimizu ◽  
Yuan-liu Chen ◽  
Wei Gao
Keyword(s):  
Interference Lithography ◽  
Polarization Modulation
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