Rhys Adams

Vanier College · Department of Physics

Les artefacts épistémiques de nature physique sont les preuves matérielles du travail effectué et produit par les étudiant·es dans le cadre de leur apprentissage. Selon la théorie socioculturelle, ils sont susceptibles de servir de médiateurs à la participation et à l'apprentissage des étudiant·es. Le rôle qu'ils jouent, et ce que cela nous apprend...

To engage students with EM waves and quantum physics, connecting it to their everyday lives and to promote “photonics awareness,” a five-part, twelve-week group research project on a photonics-based Nobel prize was developed.

We present three case studies focused on different types of feedback scenarios, each featuring a different technological tool. Results show greater student participation and engagement, and facilitation of teacher orchestration of active learning pedagogy.

We examine the design of error detection prompts which scaffold peer-feedback as a corrective process, rather than an error-identification task. After designing a series of these prompts, they were given to a class of students in an introductory physics course (treatment group). Students in the treatment group, in comparison to the control group, 1...

Optical frequency combs (OFCs) play a key role in a variety of applications and have been implemented primarily using mode-locked lasers, Kerr resonators, and electro-optic (EO) modulation. EO modulation-based OFC generation may not yield as many comb lines nor span as broad a bandwidth as mode-locked lasers or Kerr resonators; however, it offers a...

We review of recent work on developing integrated microwave photonic subsystems in silicon photonics for performing radio frequency spectral analysis, generating microwave waveforms, and filtering microwave signals.

Microwave photonic (MWP) systems exploit the advantages of photonics, especially with regards to ultrabroad bandwidth and adaptability, features that are significantly more challenging to obtain in the electronic domain. Thus, MWP systems can be used to realize a number of microwave signal processing functions including, amongst others, waveform ge...

Radio frequency spectrum analysis is an essential technique for monitoring signal quality in ultra-high-speed optical transmission, broad bandwidth photonic RF arbitrary waveform generation, and for characterization of high repetition rate optical pulse sources. Whereas the intrinsic bandwidth of electronics limits its use for RF spectrum measureme...

We demonstrate how to harness mode-selective excitation of nonlinear optical effects to perform simultaneous multi-channel RF spectrum analysis for both 640 GHz and 160 GHz waveforms using a single integrated silicon photonic device.

We review recent work on all-optical signal processing in silicon photonics. In particular, we describe the integration of a nonlinear optical loop mirror in silicon-on-insulator for applications including wavelength conversion, NRZ-to-RZ modulation format conversion, and optical time-division de-multiplexing.

An optical true time delay line (OTTDL) is a basic photonic building block that enables many microwave photonic and optical processing operations. The conventional design for an integrated OTTDL that is based on spatial diversity uses a length-variable waveguide array to create the optical time delays, which can introduce complexities in the integr...

We demonstrate 1-to-6 wavelength multicasting of a 22-GBaud 16-QAM single polarization ( $6times 88$ Gb/s) signal based on four-wave mixing in a dispersion engineered silicon nanowire. All six multicast signals perform below the bit error rate forward error correction threshold of $3.8times 10^{-3}$ , with a worst case power penalty of 8 dB. We com...

We demonstrate RF arbitrary waveform generation based on microwave photonic filtering. We use four-wave mixing in a silicon nanowire to increase the number of taps in an N-tap microwave photonic filter (MPF). Using a programmable optical filter, we can control the tap weights and, hence, the MPF response and corresponding generated waveform. We sho...

We propose and demonstrate photonic arbitrary waveform generation based on microwave photonic filtering. We show uniform and apodized waveforms, as well as tuning of the RF spectrum. We discuss how the photonic structure can be fully integrated in silicon photonics.

We demonstrate error-free wavelength conversion of 28 GBaud 16-QAM single polarization (112 Gb/s) signals based on four-wave mixing in a dispersion engineered silicon nanowire (SNW). Wavelength conversion covering the entire C-band is achieved using a single pump. We characterize the performance of the wavelength converter subsystem through the ele...

We describe the design and characterization of a silicon nanophotonic waveguide (SNW) and its use in a reconfigurable microwave photonic filter (MPF). The SNW is dispersion tailored for efficient on-chip four-wave-mixing. We use the onchip four-wave-mixing to increase the number of taps in our multiple tap delay line MPF. The tap levels are control...

We compare using nonlinear fiber to a silicon nanophotonic waveguide in implementing a reconfigurable microwave photonic filter. Additional taps are generated via four wave mixing and tap levels are controlled by a programmable filter.

We demonstrate error-free wavelength conversion of 16-QAM 28-GBaud (112 Gb/s) signals and 1-to-6 wavelength multicasting of 16-QAM 22-GBaud (6×88 Gb/s) signals based on four wave mixing in a dispersion engineered silicon nanowire.

We describe the use of various silicon photonic device technologies to implement microwave photonic filters (MPFs). We demonstrate four-wave mixing in a silicon nanowire waveguide (SNW) to increase the number of taps for MPFs based on finite impulse response filter designs. Using a 12 mm long SNW reduces the footprint by five orders of magnitude co...

We report the demonstration of mechanically induced long-period gratings in ZBLAN fibers. We also show preliminary results of an all-fiber Mach-Zehnder interferometer based on cascading these gratings.

W e report the first demonstration of a long period grating in single mode ZBLAN fibers. The grating structure is mechanically induced by pressing a threaded rod onto a section of the fiber. A notch filter response is observed both near 1365 nm and 1525 nm. The advantages of the approach include tunability, repeatability and erasability.

We investigate the operating characteristics of a semiconductor fiber laser mode-locked at 10 GHz using a nonlinear optical loop mirror. We discuss the potential application for performing all-optical clock recovery.

We present an all-optical in-band optical signal-to-noise ratio (OSNR) monitor using a nonlinear optical loop mirror. Monitoring is enabled from the nonlinear power transfer function of the loop mirror. Experimental results are provided at 40 Gb/s for three modulation formats: nonreturn-to-zero, carrier-suppressed return-to-zero, and return-to-zero...

We provide the first demonstration of encoding-decoding two-dimensional wavelength-time bipolar codes for optical code-division multiple access systems with differential detection, including a verification of multiaccess interference rejection. We implement the all-optical encoders and decoders using commercially available wavelength-division-multi...

We examine the effects of encoder and decoder mismatch due to wavelength and time chip misalignments on the bit-error rate (BER) performance of two-dimensional (2D) wavelength–time optical code-division multiple access systems. We investigate several instances of misalignment in the desired user encoder and decoder as well as in the interfering use...

We investigate the performance of a multi-user OCDMA system demonstrator with full CDR using a novel OCDMA receiver. We achieve sensitivities (BER<10^-10, 2²⁰-1 PRBS) of -19.1, -16.3, and -9.2 dBm for 1-3 users.

We report the first multiuser optical code-division multiple-access (OCDMA) system demonstrator with full clock and data recovery using a novel OCDMA receiver. We achieve receiver sensitivities of -19.1, -16.3, and -9.2 dBm for one, two, and three users, respectively, at a BER≤10^-10 using a 2²⁰-1 pseudorandom binary sequence....

We present a technology demonstrator for a 4-user 2-D wavelength-time OCDMA system based on depth-first search codes which have previously been shown to be attractive in OCDMA applications.

We investigate the impact of encoder/decoder mismatch, caused by wavelength and/or time misalignment, on the bit error rate (BER) performance of 2-D wavelength-time OCDMA systems

Written for the Photonic Systems Group, Dept. of Electrical and Computer Engineering. Thesis (M.Eng.). Includes bibliographical references.