We demonstrate a compact 4×4 wavelength selective switch with 50% fewer electrical signal pads as compared with our previous generation. We report loss and crosstalk for different paths of the switch. We measure median loss of 5.32 dB and worst case crosstalk of −35 dB. The microring resonators tune by more than one free spectral range, which is an improvement over our previous generation of switches. This switch can support 8 channels at 400 GHz spacing. We conclude that it is possible to drive both microring resonators with the same voltage and separate control is not required if the fabrication variation reduces in the future.

In this Letter, we present a new hybrid broadband-crossbar switching network that can switch multiple wavelengths on demand and can also multicast. This switch fabric is an improvement over our previous design in both switch footprint and power consumption, as it reduces the number of switching elements by approximately 50%. We compare the switch loss and crosstalk with that of a multiwavelength selective crossbar switch. We also comment on fabrication tolerance of second-order ring resonators based on experimental results of 64 second-order ring resonators, and more than 250 heaters.

We demonstrate a multi-wavelength selective crossbar switch with up to two wavelength switching capability per crosspoint. The switch has a mean path loss of 2.43 dB. We demonstrate an error free high speed PAM 4 transmission at 111.16 Gbps. We also report bounds on the port count of the switch.

We present a new switching architecture that is wavelength selective and can multicast. We compare the switch loss, number of elements and crosstalk with multi-wavelength selective crossbar switch. We report reduction in number of elements of 50%, reduced loss and a similar crosstalk as compared with multi-wavelength selective crossbar switch.

RF photonic components suffer from poor spurious-free dynamic range (SFDR) due to the high noise and distortion generated by a silicon photonic (SiP) Mach-Zehnder modulator (MZM). This work demonstrates a distributed silicon-germanium (SiGe) heterojunction bipolar transistor (HBT)-based low-noise amplifier (LNA) co-designed for linearization with a SiP MZM for a broadband radio-over-fiber (RoF) link. The SiGe LNA incorporates a distributed, tunable predistortion scheme that is inherently wideband and improves the third-order intercept point over an 18-GHz range. The assembled SiGe LNA and SiP MZM prototype demonstrates an SFDR as high as 120 dB center dot Hz(2/3) at 9 GHz, a 14-dB improvement over previous SiP RF components or RoF links.

We demonstrate an elastic multi-wavelength selective switch with up to two wavelength switching capability per crosspoint. We fabricated the switch in a silicon photonics foundry and demonstrated a 17 nm tuning range for ring resonators, with a mean path loss of 2.43 dB. This is a 70% reduction in path loss as compared to previous generations, and we demonstrate a high-speed pulse-amplitude-modulation-4 transmission at 111 Gbps through different paths of the switch.

We present the summary of experimental results on multiple generations of multiwavelength selective crossbar switches designed and fabricated in silicon photonics platform as a part of AIM Photonics. We report CW measurements of 8 × 4 and 4 × 4 switches. The latest generation of the switch improved worst case path losses by 75 % as compared with the first. We also demonstrate error free transmission in the presence of incoherent crosstalk with multiple crosstalk sources with 40 Gbps non return to zero signal and 111 Gbps four-level pulse amplitude modulation (PAM-4) transmission with hard decision forward error correction limit.

This paper investigates co-design of a broadband RF low-noise driver for silicon photonic (SiP) Mach-Zehnder modulators (MZM). The frequency response of SiP modulators demonstrates significant spur-free dynamic range (SFDR) reduction in microwave bands due to a reduction in the linearity and noise figure of the modulator. A low-noise distributed driver circuit is proposed in a 0.13μm SiGe process for the SiP modulator. The driver consists of a broadband LNA, an active balun, and a high-voltage swing driver. The MZM is fabricated in a 65-nm Silicon Photonic (SiP) process. The RoF transmitter achieves a 1-20 GHz bandwidth and an SFDR of 109 dB·Hz 2/3 at 7 GHz and 11 GHz.

Silicon photonics offer a low-cost platform for largescale RF system integration. Spur-free dynamic range (SFDR) for analog and RF photonic components is limited by electrical and optical characteristics of the p-and n-junction used to produce plasma dispersion. We propose a silicon ring modulator and demonstrate design conditions that balance the phase change between the DC Kerr and plasma dispersion effects to produce a broadband, linear electro-optical conversion. A linear phase shifter is tested within a ring modulator and an SFDR of 98 dB.Hz(2/3) is measured. With predistortion, the SFDR increases to 108 dB.Hz(2/3). In addition, the ring supports discrete multitone modulation with 16-QAM subcarriers at a 47 Gbps data rate over a 16 GHz bandwidth.

We present the theory and realization of a spectrally-partitioned 4x4 crossbar switch, with three microrings per cross-point having disjoint resonance regions within an FSR. We also describe an associated energy efficient, non-blocking wavelength assignment algorithm.

We present the theory and realization of a spectrally-partitioned 4×4 crossbar switch, with three microring resonators per cross-point having disjoint resonance regions within a free spectral range. This demonstration of the switch includes a driver. We describe an associated energy efficient, non-blocking wavelength assignment algorithm.

We present the theory and realization of a spectrally-partitioned $4\mathrm{x}4$ crossbar switch, with three microrings per cross-point having disjoint resonance regions within an FSR. We also describe an associated energy efficient, non-blocking wavelength assignment algorithm.

Here we demonstrate an 8x4 multi-wavelength selective ring resonator based crossbar switch matrix implemented in a 220-nm silicon photonics foundry for interconnecting electronic packet switches in scalable data centers. This switch design can dynamically assign up to two wavelength channels for any port-port connection, providing almost full connectivity with significant reduction in latency, cost and complexity. The switch unit cell insertion loss was measured at 0.8 dB, with an out-of-band rejection of 32 dB at 400 GHz channel separation. All the ring resonator heaters were thermally tuned, with heaters controlled by a custom 64-channel DAC driver. Detailed measurements on the whole switch showed standard deviation of 2 dB in losses across different paths, standard deviation of 0.33 nm in resonant wavelength and standard deviation of 0.01 nm/mW in ring heater tuning efficiency. Data transmission experiments at 40 Gbps showed negligible penalty due to crosstalk paths through the switch.

The dynamic range of a radio-over-fiber (RoF) link is fundamentally limited by the linearity of electro-optic modulators. Silicon photonic (SiP) processes offer significant potential for integration, but the plasma dispersion effect impacts the realizable spur-free dynamic range (SFDR). This article analyzes the underlying source of nonlinearity in SiP Mach-Zehnder modulator (MZM) and demonstrates fundamental limitations on intermodulation distortion. A SiGe low-noise distributed driver is co-designed for the SiP MZM to linearize and extend the bandwidth over which the SFDR remains high. The RoF transmitter achieves 1-20 GHz bandwidth and an SFDR of 109 dB center dot Hz(2/3) at 11 GHz. To the best of our knowledge, this is the highest SFDR demonstrated for a SiP technology without incorporating predistortion.

Heterogeneous integration of III–V semiconductor photonics combined with silicon foundry technology enables low-cost, high-performance photonic integrated circuits. Highly reliable lasers using epitaxial deposition of quantum dot lasers, with <2 mA threshold and lifetime >>100 years at 35 C have been demonstrated at University of California, Santa Barbara (UCSB) and can be manufactured at wafer scale. Reduction in the linewidth enhancement factor allows isolator-free operation. This technology enables cost-effective photonic integrated circuits for applications such as microwave photonics and data communications. Optical frequency synthesis with ∼1.5 Hz accuracy is demonstrated using heterogeneous integration. Silicon photonics applications that will benefit from future heterogeneous integration are also demonstrated, including high dynamic range microwave photonic links and optical switching technology that scales to hyperscale datacenters with hundreds of thousands of servers.

Radio-over-fiber (RoF) supports microwave and millimeter-wave communication with remote antenna heads. However, RoF links suffer from low spur-free dynamic range (SFDR) due to the low gain and high nonlinearity of silicon photonic (SiP) Mach-Zehnder modulators (MZM). This work demonstrates the first distributed silicon-germanium (SiGe) HBT LNA co-designed for linearization of a broadband SiP-based RoF link. The SiGe LNA features a distributed LNA intermodulation (IM) injection scheme that is inherently wideband, improving IIP3 over a 10 GHz range. The assembled SiGe LNA and SiP MZM prototype demonstrates an SFDR as high as 120dB·Hz 2/3 at 9 GHz, a 19 dB improvement over previous SiP RoF links.

We present a model of intermodulation distortion (IMD) in RF silicon photonic modulators to highlight mechanisms that limit the device linearity. We compare the SFDR of two MZMs to show a common IMD limitation and indicate methods to improve linearity in silicon photonic RF modulators.

We review the potential of RF photonics for microwave and millimeter-wave communication systems. The integration of photonic components in silicon CMOS processes introduces new potential for realizing RF beamforming systems with substantial signal processing and relatively low-power remote antennas. This paper reviews RF photonic link operation and reveals fundamental device challenges to wide-band high dynamic range photonic links. We demonstrate the potential for spur-free dynamic range of more than 110 dBc.Hz(2/3) is possible in silicon processes in microwave bands. We also present measurements of a silicon photonic MZM that reaches 102.8 dBc.Hz(2/3) at 1 GHz.

We demonstrate a silicon ring modulator with linear phase shift versus voltage, derived from the interplay between plasma dispersion effect and DC Kerr effect. The dynamic range is 103.6 dB. Hz 2/3 at a 1.2 GHz carrier.

Laser Technik JournalVolume 14, Issue 1 p. 1-1 EditorialFree Access Introducing AIM Photonics Advancing photonic integrated circuit (PIC) manufacturing Roger Helkey, Roger Helkey AIM Photonics, Government and Industry Outreach ExecutiveSearch for more papers by this author Roger Helkey, Roger Helkey AIM Photonics, Government and Industry Outreach ExecutiveSearch for more papers by this author First published: 17 January 2017 https://doi.org/10.1002/latj.201790011AboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. Volume14, Issue1January 2017Pages 1-1 RelatedInformation