IEEE Photonics Journal

Journal: IEEE Photonics Journal

Abbreviation

IEEE photonics j.

Publisher

IEEE

ISSN

1943-0655

Show all metadata

Search Results

Publications 1 - 10 of 14

Low-Loss Silicon Strip-to-Slot Mode Converters
Palmer, Robert J.; Alloatti, Luca; Korn, Dietmar; et al. (2013)
IEEE Photonics Journal
We demonstrate compact highly efficient broadband strip-to-slot mode converters in silicon with record-low losses of 0.02 (±0.02) dB and negligible reflections between 1480 nm and 1580 nm. The new strip-to-slot transition is logarithmically tapered, which enables a compact design. The new logarithmic tapers are compared with more conventional linearly tapered converters.
Timing Jitter Characterization of a Free-Running SESAM Mode-locked VECSEL
Wittwer, Valentin Johannes; Zaugg, Christian A.; Pallmann, Wolfgang P.; et al. (2011)
IEEE Photonics Journal
We present timing jitter measurements of an InGaAs quantum well vertical external cavity surface emitting laser (VECSEL) passively mode locked with a quantum dot semiconductor saturable absorber mirror (SESAM) at 2-GHz repetition rate. It generates 53-mW average output power in 4.6-ps pulses at 953 nm. The laser housing was optimized for high mechanical stability to reduce acoustic noise. We use a fiber-coupled multimode 808-nm pump diode, which is mounted inside the laser housing. No active cavity length stabilization is employed. The phase noise of the free-running laser integrated over a bandwidth from 100 Hz to 1 MHz corresponds to an RMS timing jitter of ≈212 fs, which is lower than previously obtained for mode-locked VECSELs. This clearly confirms the superior noise performance expected from a high-Q-cavity semiconductor laser. In contrast to edge-emitting semiconductor diode lasers, the cavity mode is perpendicular to the quantum well gain layers, which minimizes complex dispersion and nonlinear dynamics.
Digital Plasmonic Absorption Modulator Exploiting Epsilon-Near-Zero in Transparent Conducting Oxides
Koch, Ueli; Hössbacher, Claudia; Niegemann, Jens; et al. (2016)
IEEE Photonics Journal
Photonics Breakthroughs 2024: Nonlinear Photonic Computing at Scale
Wang, Hao; Hu, Jianqi; Morandi, Andrea; et al. (2025)
IEEE Photonics Journal
A photonic neural network utilizes photons instead of electrons to process information, with the prospect of higher computing efficiency, lower power consumption, and reduced latency. This paper reviews several recent breakthroughs in largescale photonic neural networks incorporating nonlinear operations. Specifically, we highlight our recent work, which leverages multiple light scattering and second harmonic generation in a slab of disordered lithium niobate nanocrystals for high-performance nonlinear photonic computing. The interplay of these optical effects not only enhances the computational capabilities of photonic neural networks but also increases the number of photonic computing operations. In addition, we discuss current challenges and outline future directions of nonlinear photonic computing. These advancements pave the way for exploring new frontiers in optical computing, unlocking opportunities for innovative experimental implementations, broad applications, and theoretical foundations of photonic neural networks.
2-D Grating Couplers for Vertical Fiber Coupling in Two Polarizations
Watanabe, Tatsuhiko; Fedoryshyn, Yuriy; Leuthold, Juerg (2019)
IEEE Photonics Journal
We demonstrate highly efficient couplers in a two-dimensional grating configuration for a vertical fiber-coupling fabricated in the silicon-on-insulator platform. A combination of sub-wavelength reflectors and blazed gratings enables both high coupling efficiency and vertical grating coupling. We experimentally achieve coupling efficiencies of -2.6 dB at 1544 nm and -3.4 dB at 1536 nm for x- and y-polarized LP01 modes, respectively. The experimental results are in good agreement with the simulated -2.4 dB coupling efficiency for both polarizations at a wavelength of 1550 nm. Simulated and measured crosstalk between two polarizations were -19 dB and <;-16 dB, respectively.
Femtosecond to Attosecond Optics
Keller, Ursula (2010)
IEEE Photonics Journal
We continue to observe strong progress moving from femtosecond to attosecond optics. Attosecond pulses are now available in many different labs with additional gating techniques which somewhat relax the requirements for the pulse duration of the intense infrared laser pulses. The pulse repetition rate still sets a limit on the signal-to-noise ratio for attosecond pump-probe measurements, and therefore, other streaking techniques have resulted in time-resolved measurements with sub-10-attosecond accuracy. Recent improvements on high-power ultrafast diode-pumped solid-state and fiber lasers will offer alternative sources for megahertz attosecond pulse generation. First proof-of-principle experiments have been demonstrated.
Long-Duration Optical Pulse Shaping and Complex Coding on SOI
Bazargani, Hamed Pishvai; Burla, Maurizio; Chen, Zhitian; et al. (2016)
IEEE Photonics Journal
This paper evaluates novel design strategies to enhance the performance of a recently proposed waveguide-based pulse-shaping method, i.e., discrete space-to-time mapping (D-STM), demonstrating the capability of the method to shape pulse waveforms with duration periods in the tens of picoseconds regime. In particular, we experimentally synthesize 70-ps high-quality flat-top pulses and a 40-ps-long 200-GBd 16-quadrature amplitude modulation (16-QAM) data sequence using D-STM in concatenated co-directional couplers. Our proposed devices have been fabricated on a silicon-on-insulator (SOI) technology platform using ultraviolet and single-etch electron-beam lithography processes. The fabricated devices are all-passive, functioning without needing post-fabrication tuning, which further proves the robust performance of the proposed scheme.
Electro-Optic Organic Crystal Silicon High-Speed Modulator
Korn, Dietmar; Jazbinsek, Mojca; Palmer, Robert J.; et al. (2014)
IEEE Photonics Journal
Silicon waveguides can be functionalized with an organic χ(2) -nonlinear cladding. This complements silicon photonics with the electro-optic (EO) effect originating from the cladding and enables functionalities such as pure phase modulation, parametric amplification, or THz-wave generation. Claddings based on a polymer matrix containing chromophores have been introduced, and their strong χ(2) nonlinearity has already been used to demonstrate ultralow power consuming modulators. However, these silicon–organic hybrid (SOH) devices inherit not only the advantageous properties; these polymer claddings require an alignment procedure called poling and must be operated well below their glass transition temperature. This excludes some applications. In contrast, claddings made from organic crystals come with a different set of properties. In particular, there is no need for poling. This new class of claddings also promises stronger resilience to high temperatures, better long-term stability, and photo-chemical stability. We report on the deposition of an organic crystal cladding of N-benzyl-2-methyl-4-nitroaniline (BNA) on silicon-on-insulator (SOI) waveguides, which have a CMOS-like metal stack on top. Adhering to such an architecture, which preserves the principal advantage of using CMOS-based silicon photonic fabrication processes, permits the first demonstration of high-speed modulation at 12.5 Gbit/s in this material class, which proves the availability of the EO effect from BNA on SOI also for other applications.
High-quality optical frequency comb by spectral slicing of spectra broadened by SPM
Hillerkuss, David; Leuthold, Juerg; et al. (2013)
IEEE Photonics Journal
This paper introduces a spectral slicing technique that extends the useful spectral range of frequency combs generated through self-phase modulation (SPM) of mode-locked laser pulses. When generating frequency combs by SPM, the spectral range with high-quality carriers is usually limited due to spectral minima carrying too little power. To overcome these limitations, we combine suitable slices of broadened and nonbroadened spectra. The concept was experimentally verified: A total number of 325 consecutive equidistant subcarriers span a bandwidth of 4 THz. All subcarriers have an optical carrier-power-to-noise-power-density ratio (OCNR) larger than 25.8 dB (0.1 nm) and were derived from one mode-locked laser with a mode linewidth of approximately 1 kHz. The signal quality of the comb and in particular of each subcarrier was ultimately tested in a terabit-per-second communication experiment. The comb quality allowed us to transmit 32.5 Tb/s over 225 km with 100 Gb/s dual polarization 16-ary quadrature amplitude modulation (16QAM) signals on each of the subcarriers.
Sub-60-fs Timing Jitter of a SESAM Modelocked VECSEL
Wittwer, Valentin Johannes; van der Linden, Robert; Tilma, Bauke W.; et al. (2013)
IEEE Photonics Journal
We present noise measurements of a pulse train emitted from an actively stabilized semiconductor-saturable-absorber-mirror (SESAM) modelocked vertical external cavity surface emitting laser (VECSEL). The laser generated 6-ps pulses with 2-GHz pulse-repetition rate and 40-mW average output power. The repetition rate was phase locked to a reference source using a piezo actuator. The timing phase noise power spectral density of the laser output was detected with a highly linear photodiode and measured with a signal source analyzer. The resulting RMS timing jitter integrated over an offset frequency range from 1 Hz to 100 MHz gives a value of below 60 fs, lower than previous modelocked VECSELs and comparable with the noise performance of ion-doped solid-state lasers. The RMS amplitude noise was below 0.4% (1 Hz to 40 MHz) and not influenced by the timing phase stabilization.

Publications 1 - 10 of 14

Journal: IEEE Photonics Journal

Abbreviation

Publisher

Journal Volumes

ISSN

Description

Filters

Search Results