Mitigation of Si nanocrystal free carrier absorption loss at 15 μm in a concentric microdisk structure

2010 ◽  
Vol 35 (13) ◽  
pp. 2182 ◽  
Author(s):  
Elton Marchena ◽  
Brandon Redding ◽  
Tim Creazzo ◽  
Dennis W. Prather
2011 ◽  
Author(s):  
H. Hazura ◽  
A. R. Hanim ◽  
B. Mardiana ◽  
Sahbudin Shaari ◽  
P. S. Menon ◽  
...  

2012 ◽  
Vol 545 ◽  
pp. 355-358
Author(s):  
Hanim Abdul Razak ◽  
Hazura Haroon ◽  
Mardiana Bidin ◽  
P. Susthitha Menon ◽  
Sahbudin Shaari

The effect of the free carrier absorption loss on the split-ridge waveguide based phase modulator is analyzed at 1.3 and 1.55 µm. The electrical device performance is predicted using the 2-D semiconductor package SILVACO software under DC operation. Based on the simulation results, it is shown that there is a penalty of increased free carrier absorption as the injected electrons and holes are getting higher. Meanwhile, the loss of the device at 1.3 µm is smaller than that of 1.55 µm at an equal applied voltage.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Wen Xiong ◽  
Jian-Wei Wang ◽  
Wei-Jun Fan ◽  
Zhi-Gang Song ◽  
Chuan-Seng Tan

AbstractWe calculate the electronic structures of Germanium nanowires by taking the effective-mass theory. The electron and hole states at the Γ-valley are studied via the eight-band k.p theory. For the [111] L-valley, we expand the envelope wave function using Bessel functions to calculate the energies of the electron states for the first time. The results show that the energy dispersion curves of electron states at the L-valley are almost parabolic irrespective of the diameters of Germanium nanowires. Based on the electronic structures, the density of states of Germanium nanowires are also obtained, and we find that the conduction band density of states mostly come from the electron states at the L-valley because of the eight equivalent degenerate L points in Germanium. Furthermore, the optical gain spectra of Germanium nanowires are investigated. The calculations show that there are no optical gain along z direction even though the injected carrier density is 4 × 1019 cm−3 when the doping concentration is zero, and a remarkable optical gain can be obtained when the injected carrier density is close to 1 × 1020 cm−3, since a large amount of electrons will prefer to occupy the low-energy L-valley. In this case, the negative optical gain will be encountered considering free-carrier absorption loss as the increase of the diameter. We also investigate the optical gain along z direction as functions of the doping concentration and injected carrier density for the doped Germanium nanowires. When taking into account free-carrier absorption loss, the calculated results show that a positive net peak gain is most likely to occur in the heavily doped nanowires with smaller diameters. Our theoretical studies are valuable in providing a guidance for the applications of Germanium nanowires in the field of microelectronics and optoelectronics.


2007 ◽  
Vol 124-126 ◽  
pp. 515-518
Author(s):  
Se Weon Choi ◽  
Hyeon Taek Son ◽  
Chang Seog Kang ◽  
Junji Nishii

Si and Er co-doped SiO2 films were fabricated by radio-frequency (RF) magnetron sputtering technique with a Si-Er-SiO2 target. The optical gain of 0.7 dB/cm was confirmed by the direct pumping of Er3+ using the laser diode (LD) of 980 nm in wavelength and 60 mW in output power. On the contrary, the pumping Si-nanocrystals by the Hg lamp 365 nm (1.5 W/cm2) induced the absorption loss above 1.48 μm region in wavelength, which was attributed to the free carrier absorption of Si-nanocrystals.


2021 ◽  
Vol 27 (3) ◽  
pp. 1-11
Author(s):  
Yen-Wei Hsueh ◽  
Chih-Hsien Cheng ◽  
Cai-Syuan Fu ◽  
Huai-Yung Wang ◽  
Bo-Ji Huang ◽  
...  

2004 ◽  
Vol 84 (13) ◽  
pp. 2265-2267 ◽  
Author(s):  
Joerg Isenberg ◽  
Wilhelm Warta

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