Sebastian Koeber

High-Speed, Low Drive-Voltage Silicon-Organic Hybrid Modulator Based on a Binary-Chromophore Electro-Optic Material

We report on the hybrid integration of silicon-on-insulator slot waveguides with organic electro-optic materials. We investigate and compare a polymer composite, a dendron-based material, and a binary-chromophore organic glass (BCOG). A record-high in-device electro-optic coefficient of 230 pm/V is found for the BCOG approach resulting in silicon-organic hybrid Mach-Zehnder modulators that feature low UπL-products of down to 0.52 Vmm and support data rates of up to 40 Gbit/s.

Silicon-organic hybrid (SOH) frequency comb sources for terabit/s data transmission

We demonstrate frequency comb sources based on silicon-organic hybrid (SOH) electro-optic modulators. Frequency combs with line spacings of 25 GHz and 40 GHz are generated, featuring flat-top spectra with less than 2 dB power variations over up to 7 lines. The combs are used for WDM data transmission at terabit/s data rates and distances of up to 300 km.

Low-power silicon-organic hybrid (SOH) modulators for advanced modulation formats

We demonstrate silicon-organic hybrid (SOH) electro-optic modulators that enable quadrature phase-shift keying (QPSK) and 16-state quadrature amplitude modulation (16QAM) with high signal quality and record-low energy consumption. SOH integration combines highly efficient electro-optic organic materials with conventional silicon-on-insulator (SOI) slot waveguides, and allows to overcome the intrinsic limitations of silicon as an optical integration platform. We demonstrate QPSK and 16QAM signaling at symbol rates of 28 GBd with peak-to-peak drive voltages of 0.6 V(pp). For the 16QAM experiment at 112 Gbit/s, we measure a bit-error ratio of 5.1 × 10⁻⁵ and a record-low energy consumption of only 19 fJ/bit.

40 GBd 16QAM Signaling at 160 Gb/s in a Silicon-Organic Hybrid Modulator

We demonstrate for the first time generation of 16-state quadrature amplitude modulation (16QAM) signals at a symbol rate of 40 GBd using silicon-based modulators. Our devices exploit silicon-organic hybrid integration, which combines silicon-on-insulator slot waveguides with electro-optic cladding materials to realize highly efficient phase shifters. The devices enable 16QAM signaling and quadrature phase shift keying at symbol rates of 40 GBd and 45 GBd, respectively, leading to line rates of up to 160 Gb/s on a single wavelength and in a single polarization. This is the highest value demonstrated by a silicon-based device up to now. The energy consumption for 16QAM signaling amounts to less than 120 fJ/bit-one order of magnitude below that of conventional silicon photonic 16QAM modulators.

Lasing in silicon-organic hybrid waveguides.

Silicon photonics enables large-scale photonic–electronic integration by leveraging highly developed fabrication processes from the microelectronics industry. However, while a rich portfolio of devices has already been demonstrated on the silicon platform, on-chip light sources still remain a key challenge since the indirect bandgap of the material inhibits efficient photon emission and thus impedes lasing. Here we demonstrate a class of infrared lasers that can be fabricated on the silicon-on-insulator (SOI) integration platform. The lasers are based on the silicon–organic hybrid (SOH) integration concept and combine nanophotonic SOI waveguides with dye-doped organic cladding materials that provide optical gain. We demonstrate pulsed room-temperature lasing with on-chip peak output powers of up to 1.1 W at a wavelength of 1,310 nm. The SOH approach enables efficient mass-production of silicon photonic light sources emitting in the near infrared and offers the possibility of tuning the emission wavelength over a wide range by proper choice of dye materials and resonator geometry.

Densely Packed Microgoblet Laser Pairs for Cross-Referenced Biomolecular Detection

Microgoblet laser pairs are presented for cross‐referenced on‐chip biomolecular sensing. Parallel readout of the microlasers facilitates effective mutual filtering of highly localized refractive index and temperature fluctuations in the analyte. Cross‐referenced detection of two different types of proteins and complete chemical transducer reconfiguration is demonstrated. Selective surface functionalization of the individual lasers with high spatial accuracy is achieved by aligned microcontact stamping.

Efficient free-space read-out of WGM lasers using circular micromirrors.

We report on efficient free-space read-out of whispering-gallery mode microlasers using circular micromirrors. A ten-fold improvement in detection efficiency can be achieved by directing emission from all azimuthal angles of the cavity to the detector.

Connecting silicon photonic circuits to multi-core fibers by photonic wire bonding

A four-core fiber is coupled to a silicon photonic chip by photonic wire bonding. The technique does not require active alignment and is well suited for automated fabrication. Measured coupling losses amount to 1.7 dB.

40 GBd 16QAM Modulation at 160 Gbit/s in a Silicon-Organic Hybrid (SOH) Modulator

We demonstrate 16QAM and QPSK modulation at symbol rates of 40 GBd and 45 GBd using a silicon-based IQ modulator. The device enables data rates up to 160 Gbit/s in a single polarization with an estimated energy consumption of 120fJ/bit.

High-speed silicon-organic hybrid (SOH) modulators with 230 pm/V electro-optic coefficient using advanced materials

We report on record-high electro-optic coefficients of up to 230 pm/V in silicon slot waveguide modulators. The modulators allow for low drive voltage at 40 Gbit/s at a device length of only 250 μm.