Demonstration of a silicon Raman laser
TL;DR: The demonstration of the first silicon Raman laser using a silicon waveguide as the gain medium and has a clear threshold at 9 W peak pump pulse power and a slope efficiency of 8.5%.
Abstract: We report the demonstration of the first silicon Raman laser. Experimentally, pulsed Raman laser emission at 1675 nm with 25 MHz repetition rate is demonstrated using a silicon waveguide as the gain medium. The laser has a clear threshold at 9 W peak pump pulse power and a slope efficiency of 8.5%.
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TL;DR: Electro-optic modulators are one of the most critical components in optoelectronic integration, and decreasing their size may enable novel chip architectures, and here a high-speed electro-optical modulator in compact silicon structures is experimentally demonstrated.
Abstract: Metal interconnections are expected to become the limiting factor for the performance of electronic systems as transistors continue to shrink in size. Replacing them by optical interconnections, at different levels ranging from rack-to-rack down to chip-to-chip and intra-chip interconnections, could provide the low power dissipation, low latencies and high bandwidths that are needed. The implementation of optical interconnections relies on the development of micro-optical devices that are integrated with the microelectronics on chips. Recent demonstrations of silicon low-loss waveguides, light emitters, amplifiers and lasers approach this goal, but a small silicon electro-optic modulator with a size small enough for chip-scale integration has not yet been demonstrated. Here we experimentally demonstrate a high-speed electro-optical modulator in compact silicon structures. The modulator is based on a resonant light-confining structure that enhances the sensitivity of light to small changes in refractive index of the silicon and also enables high-speed operation. The modulator is 12 micrometres in diameter, three orders of magnitude smaller than previously demonstrated. Electro-optic modulators are one of the most critical components in optoelectronic integration, and decreasing their size may enable novel chip architectures.
2,336 citations
TL;DR: An overview of the current state-of-the-art in silicon nanophotonic ring resonators is presented in this paper, where the basic theory of ring resonance is discussed and applied to the peculiarities of submicron silicon photonic wire waveguides: the small dimensions and tight bend radii, sensitivity to perturbations and the boundary conditions of the fabrication processes.
Abstract: An overview is presented of the current state-of-the-art in silicon nanophotonic ring resonators. Basic theory of ring resonators is discussed, and applied to the peculiarities of submicron silicon photonic wire waveguides: the small dimensions and tight bend radii, sensitivity to perturbations and the boundary conditions of the fabrication processes. Theory is compared to quantitative measurements. Finally, several of the more promising applications of silicon ring resonators are discussed: filters and optical delay lines, label-free biosensors, and active rings for efficient modulators and even light sources.
1,989 citations
TL;DR: In this paper, the state-of-the-art CMOS silicon-on-insulator (SOI) foundries are now being utilized in a crucial test of 1.55mum monolithic optoelectronic (OE) integration, a test sponsored by the Defense Advanced Research Projects Agency (DARPA).
Abstract: The pace of the development of silicon photonics has quickened since 2004 due to investment by industry and government. Commercial state-of-the-art CMOS silicon-on-insulator (SOI) foundries are now being utilized in a crucial test of 1.55-mum monolithic optoelectronic (OE) integration, a test sponsored by the Defense Advanced Research Projects Agency (DARPA). The preliminary results indicate that the silicon photonics are truly CMOS compatible. RD however, lasing has not yet been attained. The new paradigm for the Si-based photonic and optoelectric integrated circuits is that these chip-scale networks, when suitably designed, will operate at a wavelength anywhere within the broad spectral range of 1.2-100 mum, with cryocooling needed in some cases
1,789 citations
Cites methods from "Demonstration of a silicon Raman la..."
...The development of the silicon Raman laser, mainly by the groups at UCLA [23] and Intel Corporation [24], was a dramatic milestone in the history of silicon photonics....
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...Jalali and coworkers at UCLA have experimentally proven an alternative approach in which the photonic layer (containing, for example, an inplane-coupled microdisk resonator) is buried beneath the silicon CMOS layer in a subterranean fashion [22]....
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...The organizations currently investigating electronic and photonic integration under DARPA EPIC are the BAE Systems team (electronic warfare application-specific EPIC), the Luxtera team (CMOS photonics technology), the Lincoln Laboratory team (high-resolution optical sampling technology), California Institute of Technology (optical signal amplification in silicon), UCLA (nonlinear silicon photonics), Translucent (low-cost buried photonic layer beneath CMOS), University of Michigan (CMOS-compatible quantum dot lasers grown directly on Si/SiGe), Stanford University (germanium quantum wells on silicon substrate for optical modulation), and Brown University (all-silicon periodic nanometric superlattices toward a silicon laser)....
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...The UCLA approach offers simple fabrication, however, they must control the transistor processing temperatures so as not to injure the active photonic materials below the CMOS....
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...Currently, scientists from California Institute of Technology, Stanford, Harvard, UCLA, and UCSD are researching “Novel devices for plasmonic and nanophotonic networks” described at www.plasmonmuri.caltech.edu/research/index.html....
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Journal Article•
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TL;DR: The silicon chip has been the mainstay of the electronics industry for the last 40 years and has revolutionized the way the world operates as mentioned in this paper, however, any optical solution must be based on low-cost technologies if it is to be applied to the mass market.
Abstract: The silicon chip has been the mainstay of the electronics industry for the last 40 years and has revolutionized the way the world operates. Today, a silicon chip the size of a fingernail contains nearly 1 billion transistors and has the computing power that only a decade ago would take up an entire room of servers. As the relentless pursuit of Moore's law continues, and Internet-based communication continues to grow, the bandwidth demands needed to feed these devices will continue to increase and push the limits of copper-based signaling technologies. These signaling limitations will necessitate optical-based solutions. However, any optical solution must be based on low-cost technologies if it is to be applied to the mass market. Silicon photonics, mainly based on SOI technology, has recently attracted a great deal of attention. Recent advances and breakthroughs in silicon photonic device performance have shown that silicon can be considered a material onto which one can build optical devices. While significant efforts are needed to improve device performance and commercialize these technologies, progress is moving at a rapid rate. More research in the area of integration, both photonic and electronic, is needed. The future is looking bright. Silicon photonics could provide low-cost opto-electronic solutions for applications ranging from telecommunications down to chip-to-chip interconnects, as well as emerging areas such as optical sensing technology and biomedical applications. The ability to utilize existing CMOS infrastructure and manufacture these silicon photonic devices in the same facilities that today produce electronics could enable low-cost optical devices, and in the future, revolutionize optical communications
1,479 citations
Cites background from "Demonstration of a silicon Raman la..."
...The main challenge that remains in the path to an electrically pumped laser is highlighted in Fig....
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TL;DR: The demonstration of a continuous-wave silicon Raman laser is demonstrated and it is shown that TPA-induced FCA in silicon can be significantly reduced by introducing a reverse-biased p-i-n diode embedded in a silicon waveguide.
Abstract: Achieving optical gain and/or lasing in silicon has been one of the most challenging goals in silicon-based photonics because bulk silicon is an indirect bandgap semiconductor and therefore has a very low light emission efficiency. Recently, stimulated Raman scattering has been used to demonstrate light amplification and lasing in silicon. However, because of the nonlinear optical loss associated with two-photon absorption (TPA)-induced free carrier absorption (FCA), until now lasing has been limited to pulsed operation. Here we demonstrate a continuous-wave silicon Raman laser. Specifically, we show that TPA-induced FCA in silicon can be significantly reduced by introducing a reverse-biased p-i-n diode embedded in a silicon waveguide. The laser cavity is formed by coating the facets of the silicon waveguide with multilayer dielectric films. We have demonstrated stable single mode laser output with side-mode suppression of over 55 dB and linewidth of less than 80 MHz. The lasing threshold depends on the p-i-n reverse bias voltage and the laser wavelength can be tuned by adjusting the wavelength of the pump laser. The demonstration of a continuous-wave silicon laser represents a significant milestone for silicon-based optoelectronic devices.
1,267 citations
References
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Book•
01 Jan 1989TL;DR: The field of nonlinear fiber optics has advanced enough that a whole book was devoted to it as discussed by the authors, which has been translated into Chinese, Japanese, and Russian languages, attesting to the worldwide activity in the field.
Abstract: Nonlinear fiber optics concerns with the nonlinear optical phenomena occurring inside optical fibers. Although the field ofnonlinear optics traces its beginning to 1961, when a ruby laser was first used to generate the second-harmonic radiation inside a crystal [1], the use ofoptical fibers as a nonlinear medium became feasible only after 1970 when fiber losses were reduced to below 20 dB/km [2]. Stimulated Raman and Brillouin scatterings in single-mode fibers were studied as early as 1972 [3] and were soon followed by the study of other nonlinear effects such as self- and crossphase modulation and four-wave mixing [4]. By 1989, the field ofnonlinear fiber optics has advanced enough that a whole book was devoted to it [5]. This book or its second edition has been translated into Chinese, Japanese, and Russian languages, attesting to the worldwide activity in the field of nonlinear fiber optics.
15,770 citations
TL;DR: In this paper, the energy and polarization characteristics of the one and two-phonon Raman spectrum have been measured using a 180\ifmmode^\circ\else\text degree\fi{} backscattering technique.
Abstract: The energy and polarization characteristics of the one- and two-phonon Raman spectrum have been measured using a 180\ifmmode^\circ\else\textdegree\fi{} backscattering technique. The two-phonon spectrum was measured at 20, 80, and 305\ifmmode^\circ\else\textdegree\fi{}K. The one-phonon spectrum was measured at 17, 30, 80, and 305 \ifmmode^\circ\else\textdegree\fi{}K. The one-phonon line of symmetry ${\ensuremath{\Gamma}}_{25}$, was shown to be Lorentzian and to have a deconvoluted half-width at 17 \ifmmode^\circ\else\textdegree\fi{}K of 1.45 \ifmmode\pm\else\textpm\fi{} 0.05 ${\mathrm{cm}}^{\ensuremath{-}1}$. The two-phonon Raman spectrum was used to determine phonon energies at the four critical points $\ensuremath{\Gamma}$, $X$, $L$, and $W$.
581 citations
"Demonstration of a silicon Raman la..." refers background in this paper
...6 THz) and a pump wavelength of 1540nm [1, 11-12]....
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TL;DR: It is shown that pulsed pumping with a pulse width narrower than the carrier recombination lifetime in SOI significantly reduces the free carrier generation rate due to two-photon absorption (TPA) in silicon.
Abstract: We observe for the first time net optical gain in a low loss silicon waveguide in silicon-on-insulator (SOI) based on stimulated Raman scattering with a pulsed pump laser at 1.545 μm. We show that pulsed pumping with a pulse width narrower than the carrier recombination lifetime in SOI significantly reduces the free carrier generation rate due to two-photon absorption (TPA) in silicon. For a 4.8 cm long waveguide with an effective core area of ~1.57 μm2, we obtained a net gain of 2 dB with a pump pulse width of ~17 ns and a peak pump power of ~470 mW inside the waveguide.
241 citations
"Demonstration of a silicon Raman la..." refers background in this paper
...The interest in Raman scattering has increased lately and a number of reports describing net waveguide gain [4-6] and fiber-to-fiber gain [7-8] have been published....
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TL;DR: The first measurements of spontaneous Raman scattering from silicon waveguides are reported, suggesting that a silicon optical amplifier is within reach as it lowers the pump power required for the onset ofRaman scattering.
Abstract: We report the first measurements of spontaneous Raman scattering from silicon waveguides Using a 143 m pump, both forward and backward scattering were measured at 154 m from Silicon-On-Insulator (SOI) waveguides From the dependence of the Stokes power vs pump power, we extract a value of (41 +/- 25) x 10-7 cm-1 Sr-1 for the Raman scattering efficiency The results suggest that a silicon optical amplifier is within reach The strong optical confinement in silicon waveguides is an attractive property as it lowers the pump power required for the onset of Raman scattering The SiGe material system is also discussed
181 citations
"Demonstration of a silicon Raman la..." refers background in this paper
...6 THz) and a pump wavelength of 1540nm [1, 11-12]....
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...In the last few years, spontaneous and stimulated Raman scattering have been demonstrated in Silicon-on-insulator (SOI) waveguides, showing the possibility of active functionalities based on Raman effect [1-2]....
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TL;DR: The first observation of parametric down-conversion in silicon is reported and it is shown that the power conversion efficiency is a strong function of phase mismatch inside the waveguide.
Abstract: The first observation of parametric down-conversion in silicon is reported. Conversion from 1542.3nm to 1328.8nm is achieved using a CW pump laser at 1427 nm. The conversion occurs via Coherent Anti-Stokes Raman Scattering (CARS) in which two pump photons and one Stokes photon couple through a zone-center optical phonon to an anti-Stokes photon. The maximum measured Stokes/anti-Stokes power conversion efficiency is 1×10-5. The value depends on the effective pump power, the Stimulated Raman Scattering (SRS) coefficient of bulk silicon, and waveguide dispersion. It is shown that the power conversion efficiency is a strong function of phase mismatch inside the waveguide.
160 citations
"Demonstration of a silicon Raman la..." refers methods or result in this paper
...This is consistent with our previous observation of parametric Raman wavelength conversion in silicon waveguides [3]....
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...This was followed by the demonstration of coherent anti-Stokes Raman scattering [3] in similar structures....
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