Abstract
Dynamic optical control of infrared (IR) transparency and refractive index is achieved using boron-doped silicon nanocrystals excited with mid-IR optical pulses. Unlike previous silicon-based optical switches, large changes in transmittance are achieved without a fabricated structure by exploiting strong light coupling of the localized surface plasmon resonance (LSPR) produced from free holes of p-Type silicon nanocrystals. The choice of optical excitation wavelength allows for selectivity between hole heating and carrier generation through intraband or interband photoexcitation, respectively. Mid-IR optical pumping heats the free holes of p-Si nanocrystals to effective temperatures greater than 3500 K. Increases of the hole effective mass at high effective hole temperatures lead to a subpicosecond change of the dielectric function, resulting in a redshift of the LSPR, modulating mid-IR transmission by as much as 27%, and increasing the index of refraction by more than 0.1 in the mid-IR. Low hole heat capacity dictates subpicosecond hole cooling, substantially faster than carrier recombination, and negligible heating of the Si lattice, permitting mid-IR optical switching at terahertz repetition frequencies. Further, the energetic distribution of holes at high effective temperatures partially reverses the Burstein-Moss effect, permitting the modulation of transmittance at telecommunications wavelengths. The results presented here show that doped silicon, particularly in micro-or nanostructures, is a promising dynamic metamaterial for ultrafast IR photonics.
| Original language | English |
|---|---|
| Pages (from-to) | 6409-6414 |
| Number of pages | 6 |
| Journal | Nano Letters |
| Volume | 17 |
| Issue number | 10 |
| DOIs | |
| Publication status | Published - Oct 11 2017 |
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Keywords
- doping
- infrared
- optical switching
- plasmonics
- Silicon photonics
ASJC Scopus subject areas
- Bioengineering
- Chemistry(all)
- Materials Science(all)
- Condensed Matter Physics
- Mechanical Engineering
Cite this
Ultrafast Silicon Photonics with Visible to Mid-Infrared Pumping of Silicon Nanocrystals. / Diroll, Benjamin T.; Schramke, Katelyn S.; Guo, Peijun; Kortshagen, Uwe R.; Schaller, Richard D.
In: Nano Letters, Vol. 17, No. 10, 11.10.2017, p. 6409-6414.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Ultrafast Silicon Photonics with Visible to Mid-Infrared Pumping of Silicon Nanocrystals
AU - Diroll, Benjamin T.
AU - Schramke, Katelyn S.
AU - Guo, Peijun
AU - Kortshagen, Uwe R.
AU - Schaller, Richard D
PY - 2017/10/11
Y1 - 2017/10/11
N2 - Dynamic optical control of infrared (IR) transparency and refractive index is achieved using boron-doped silicon nanocrystals excited with mid-IR optical pulses. Unlike previous silicon-based optical switches, large changes in transmittance are achieved without a fabricated structure by exploiting strong light coupling of the localized surface plasmon resonance (LSPR) produced from free holes of p-Type silicon nanocrystals. The choice of optical excitation wavelength allows for selectivity between hole heating and carrier generation through intraband or interband photoexcitation, respectively. Mid-IR optical pumping heats the free holes of p-Si nanocrystals to effective temperatures greater than 3500 K. Increases of the hole effective mass at high effective hole temperatures lead to a subpicosecond change of the dielectric function, resulting in a redshift of the LSPR, modulating mid-IR transmission by as much as 27%, and increasing the index of refraction by more than 0.1 in the mid-IR. Low hole heat capacity dictates subpicosecond hole cooling, substantially faster than carrier recombination, and negligible heating of the Si lattice, permitting mid-IR optical switching at terahertz repetition frequencies. Further, the energetic distribution of holes at high effective temperatures partially reverses the Burstein-Moss effect, permitting the modulation of transmittance at telecommunications wavelengths. The results presented here show that doped silicon, particularly in micro-or nanostructures, is a promising dynamic metamaterial for ultrafast IR photonics.
AB - Dynamic optical control of infrared (IR) transparency and refractive index is achieved using boron-doped silicon nanocrystals excited with mid-IR optical pulses. Unlike previous silicon-based optical switches, large changes in transmittance are achieved without a fabricated structure by exploiting strong light coupling of the localized surface plasmon resonance (LSPR) produced from free holes of p-Type silicon nanocrystals. The choice of optical excitation wavelength allows for selectivity between hole heating and carrier generation through intraband or interband photoexcitation, respectively. Mid-IR optical pumping heats the free holes of p-Si nanocrystals to effective temperatures greater than 3500 K. Increases of the hole effective mass at high effective hole temperatures lead to a subpicosecond change of the dielectric function, resulting in a redshift of the LSPR, modulating mid-IR transmission by as much as 27%, and increasing the index of refraction by more than 0.1 in the mid-IR. Low hole heat capacity dictates subpicosecond hole cooling, substantially faster than carrier recombination, and negligible heating of the Si lattice, permitting mid-IR optical switching at terahertz repetition frequencies. Further, the energetic distribution of holes at high effective temperatures partially reverses the Burstein-Moss effect, permitting the modulation of transmittance at telecommunications wavelengths. The results presented here show that doped silicon, particularly in micro-or nanostructures, is a promising dynamic metamaterial for ultrafast IR photonics.
KW - doping
KW - infrared
KW - optical switching
KW - plasmonics
KW - Silicon photonics
UR - http://www.scopus.com/inward/record.url?scp=85031303760&partnerID=8YFLogxK
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U2 - 10.1021/acs.nanolett.7b03393
DO - 10.1021/acs.nanolett.7b03393
M3 - Article
VL - 17
SP - 6409
EP - 6414
JO - Nano Letters
JF - Nano Letters
SN - 1530-6984
IS - 10
ER -