Supercontinuum generation in hydrogenated amorphous silicon waveguides at telecommunication wavelengths

Safioui, Jassem; Léo, François; Kuyken, Bart; Gorza, Simon-Pierre; Selvaraja, Shankar Kumar; Baets, Roel; Emplit, Philippe; Roelkens, Günther; Massar, Serge

doi:10.1364/oe.22.003089

Cited by 44 publications

(22 citation statements)

References 29 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In this ps regime, the degradation also reduces the SC bandwidth over time [3]. However, no degradation was observed with femtosecond pulses even for larger average power and pulse energy than for the experiment reported in [3]. The transmission, recorded during two hours, shows no measurable decrease of its value.…”

mentioning

confidence: 70%

“…This larger value results in lower two-photon absorption (TPA) and TPA induced free-carrier absorption, which are known to strongly limit the efficiency of nonlinear interactions [2]. SC generation has been recently observed in a-Si:H waveguide with picosecond pulses [3]. However in this latter work material degradation has been reported and we expect this degradation to be reduced in the femtosecond regime.…”

mentioning

confidence: 74%

See 1 more Smart Citation

Supercontinuum Generation in Hydrogenated Amorphous Silicon Waveguides in the Femtosecond Regime

et al. 2014

View full text Add to dashboard Cite

Supercontinuum generation in CMOS compatible hydrogenated amorphous silicon waveguides with femtosecond pulses at telecommunication wavelengths is experimentally studied. It is shown that stable 540 nm broad supercontinua can be obtained in 1 cm-long waveguides. Extreme spectral broadening that occurs when narrowband input pulses propagate in nonlinear optical media is known as supercontinuum (SC) generation [1]. In nonlinear bulk media, ultrahigh pulse energy delivered by cumbersome sources was required to observe this spectral widening. However, with the advent of guiding structures such as optical fibers, SC generation is possible with much lower pulse energy (and even with continuous waves) thanks to dispersion engineering and effective nonlinearity enhancement. Nevertheless, the integration of such sources still remains an important topic in photonic research owing to their possible applications. Hydrogenated amorphous silicon (a-Si:H) waveguides, thanks to their CMOS compatibility and high nonlinearity, are one of the most promising ultra-compact nonlinear devices for SC generation.In this work we focus on the generation of SC with femtosecond pulses in a-Si:H waveguides at telecommunication wavelengths around 1.55 µm. The advantage of this material over crystalline silicon is its larger bandgap of about 1.6 eV. This larger value results in lower two-photon absorption (TPA) and TPA induced free-carrier absorption, which are known to strongly limit the efficiency of nonlinear interactions [2]. SC generation has been recently observed in a-Si:H waveguide with picosecond pulses [3]. However in this latter work material degradation has been reported and we expect this degradation to be reduced in the femtosecond regime.Experiments were performed in 1 cm-long waveguides (cross-section 220⇥500 nm 2 ) fabricated using deep UV optical lithography and dry etching [4]. At telecommunication wavelengths, these waveguides are characterized by a linear loss of a = 3 dB/cm and a nonlinear parameter g = (740 + i 31) W 1 m 1 . At 1550 nm, the dispersion is anomalous and the GVD value has been estimated to be b 2 =-2 ps 2 /m [5]. The source is an OPO laser delivering pulses of about 150 fs around 1550 nm with a repetition rate of 82 MHz. The laser beam was coupled into the waveguide by means of a ⇥60 microscope objective to excite the quasi-TE mode of the waveguide. At the waveguide output, the light was collected with a lensed fiber (NA=0.4).Typical SC spectra at the waveguide output are reported in Fig.1(a). At an on chip peak power of 18 W, i.e. a pulse energy of 2.7 pJ, the spectrum extends from 1380 nm to 1920 nm at -20 dB from the peak maximum [see red curve in Fig.1(a)]. This spectrum is likely the result of self-phase modulation, soliton fission and dispersive wave generation. This latter phenomenon is an energy transfer from a soliton to a narrow frequency band in the normal GVD regime, and the peak around 1840 nm at 2 W input power is probably the signature of such a dispersive wave. The detailed physica...

show abstract

mentioning

confidence: 70%

mentioning

confidence: 74%

Supercontinuum Generation in Hydrogenated Amorphous Silicon Waveguides in the Femtosecond Regime

et al. 2014

View full text Add to dashboard Cite

show abstract

“…Although more research is needed, these preliminary results indicate that two-photon absorption is likely related to the material degradation. Furthermore, it is interesting to note that in a set of experiments involving 150 fs pulses to generate a supercontinuum at telecom wavelengths [45], no degradation could be observed. However, it also needs to be emphasized that other groups have demonstrated aSi:H waveguides, which are chemically stable at telecom wavelengths [36,37].…”

Section: Hydrogenated Amorphous Siliconmentioning

confidence: 99%

Nonlinear optical interactions in silicon waveguides

et al. 2017

View full text Add to dashboard Cite

Abstract:The strong nonlinear response of silicon photonic nanowire waveguides allows for the integration of nonlinear optical functions on a chip. However, the detrimental nonlinear optical absorption in silicon at telecom wavelengths limits the efficiency of many such experiments. In this review, several approaches are proposed and demonstrated to overcome this fundamental issue. By using the proposed methods, we demonstrate amongst others supercontinuum generation, frequency comb generation, a parametric optical amplifier, and a parametric optical oscillator.

show abstract

Section: Ocis Codesmentioning

confidence: 99%

“…These structures are however difficult to design and optimize and operate well only using specific drive currents. Alternatively, broadband supercontinuum sources can be considered, but these typically require ultra-short pulse * Corresponding author: andreasdegroote@intec.ugent.be sources that cannot yet be integrated on the silicon-oninsulator waveguide circuit [7].To address these limitations, we designed and demonstrated a superluminescent single mode light emitting diode with different active sections having a different band gap, integrated on a silicon waveguide circuit. Thanks to the implantation enhanced disordering quantum well intermixing technique (IED-QWI), we can blueshift certain areas of the to-be-bonded InP die [8].…”

mentioning

confidence: 99%

Heterogeneously integrated III–V-on-silicon multibandgap superluminescent light-emitting diode with 290 nm optical bandwidth

et al. 2014

View full text Add to dashboard Cite

For the first time, quantum well intermixing and multiple die bonding of InP on a silicon photonic waveguide circuit were combined. In this manner, a broadband superluminescent III-V on silicon LED was realized. The device consists of four sections with different band gaps, centered around 1300nm, 1380nm, 1460nm and 1540nm. The fabricated LEDs were connected on-chip in a serial way, where the light generated in the smaller band gap sections travels through the larger band gap sections. By balancing the pump current in the four LEDs we achieved 292nm of 3dB bandwidth and an on-chip power of -8dBm. OCIS codes:( While originally conceived for data and telecom applications, a broader range of applications is rapidly emerging using silicon photonics as a potential integration platform. Using standard CMOS fabrication techniques the silicon photonic chip fabrication can achieve very high yield. However, it is difficult to realize a monolithically integrated light source on silicon due to its indirect band gap. Therefore III-V compounds such as InP are heterogeneously integrated on silicon-on-insulator (SOI) waveguide circuits. In these integrated devices the gain is provided by the active region originally grown on a III-V substrate.Superluminescent diodes (SLDs) are suitable for numerous applications ranging from optical component testing to sensing applications (e.g. gyroscopes) as well as medical imaging (e.g. optical coherence tomography). For these applications, large bandwidth is of critical importance (300nm of bandwidth leads to ±3µm of resolution in OCT). There are different approaches of extending the bandwidth of the III-V gain medium, among which a dual quantum well design [4], multistate quantum wells [5] and quantum dots [6]. These structures are however difficult to design and optimize and operate well only using specific drive currents. Alternatively, broadband supercontinuum sources can be considered, but these typically require ultra-short pulse * Corresponding author: andreasdegroote@intec.ugent.be sources that cannot yet be integrated on the silicon-oninsulator waveguide circuit [7].To address these limitations, we designed and demonstrated a superluminescent single mode light emitting diode with different active sections having a different band gap, integrated on a silicon waveguide circuit. Thanks to the implantation enhanced disordering quantum well intermixing technique (IED-QWI), we can blueshift certain areas of the to-be-bonded InP die [8]. On top of that, we can bond several dies on one SOI waveguide circuit [9]. To our knowledge, it is the first time that these two techniques have been combined, although they are very complementary. With this achievement, we merged four different band gaps in a serial manner, as indicated in figure 1a.Since two epitaxial layer stacks are bonded side by side, we have a large design freedom for the epitaxial design. Our layer stack of choice is described in table 1. The downside of this multiple die bonding is the reduced flexibility in the positioning of th...

show abstract

Supercontinuum generation in hydrogenated amorphous silicon waveguides at telecommunication wavelengths

Cited by 44 publications

References 29 publications

Supercontinuum Generation in Hydrogenated Amorphous Silicon Waveguides in the Femtosecond Regime

Supercontinuum Generation in Hydrogenated Amorphous Silicon Waveguides in the Femtosecond Regime

Nonlinear optical interactions in silicon waveguides

Heterogeneously integrated III–V-on-silicon multibandgap superluminescent light-emitting diode with 290 nm optical bandwidth

Contact Info

Product

Resources

About