With continued steep growth in the volume of data transmitted over optical networks there is a widely recognized need for more sophisticated photonics technologies to forestall a 'capacity crunch' 1 . A promising solution is to open new spectral regions at wavelengths near 2 μm and to exploit the long-wavelength transmission and amplification capabilities of hollowcore photonic-bandgap fibres 2,3 and the recently available thulium-doped fibre amplifiers 4 . To date, photodetector devices for this window have largely relied on III-V materials 5 or, where the benefits of integration with silicon photonics are sought, GeSn alloys, which have been demonstrated thus far with only limited utility 6-9 . Here, we describe a silicon photodiode operating at 20 Gbit s -1 in this wavelength region. The detector is compatible with standard silicon processing and is integrated directly with silicon-on-insulator waveguides, which suggests future utility in silicon-based mid-infrared integrated optics for applications in communications.The advantages of silicon photonics, which have been well documented for traditional communication wavelengths around 1.3 and 1.5 µm (refs 8,9), extend to operation in the mid-infrared (MIR) region 10 . Silicon photonic components are fabricated using complementary metal-oxide semiconductor (CMOS)-compatible technologies, with the potential for integration with electronic control. Recently, groups have demonstrated several silicon-based components operating in the MIR wavelength range of 2-20 μm, including low-loss waveguides, couplers, splitters and multiplexers 11 , as well as some with hybrid active functionality 12,13 . However, photodetectors that are compatible with silicon waveguides, are capable of detection beyond 2 μm, and operate at the bandwidths required by future optical communication networks remain elusive. The sig-
We describe the fabrication and operation of an optical power monitor, monolithically integrated with a silicon-on-insulator rib waveguide. The device consists of a p+-v-n+ structure with a detection volume coincident with the single-mode supporting waveguide. Detection of optical signals at wavelengths around 1550nm is significantly enhanced by the introduction of midband-gap generation centers, which provide partial absorption of the infrared light. The most efficient device extracted 19% of optical power from the waveguide and showed a responsivity of 3mA∕W. These devices are fabricated using current standard processing technology and are fully compatible with silicon waveguide technology and integrated operational amplifier circuits.
We describe, model and demonstrate a tunable micro-ring resonator integrated monolithically with a photodiode in a silicon waveguide device. The photodiode is made sensitive to wavelengths at and around 1550nm via the introduction of lattice damage through selective ion implantation. The ring resonator enhances detector responsivity in a 60 mum long waveguide photodiode such that it is 0.14 A/W at -10Vbias with less than 0.2 nA leakage current. The device is tunable such that resonance (and thus detection) can be achieved at any wavelength from 1510 - 1600 nm. We also demonstrate use of the device as a digital switch with integrated power monitoring, 20 dB extinction, and no optical power tapped from the output path to the photodiode. A theoretical description suggests that for a critically coupled resonator where the round trip loss is dominated by the excess defects used to mediate detection, the maximum responsivity is independent of device length. This leads to the possibility of extremely small detector geometries in silicon photonics with no requirement for the use of III-V materials or germanium.
Micropixelated blue (470 nm) and ultraviolet (370 nm) AlInGaN light emitting diode ('micro-LED') arrays have been fabricated in flip-chip format with different pixel diameters (72 microm and 30 microm at, respectively, 100 and 278 pixels/mm(2)). Each micro-LED pixel can be individually-addressed and the devices possess a specially designed n-common contact incorporated to ensure uniform current injection and consequently uniform light emission across the array. The flip-chip micro-LEDs show, per pixel, high continuous output intensity of up to 0.55 microW/microm(2) (55 W/cm(2)) at an injection current density of 10 kA/cm(2) and can sustain continuous injection current densities of up to 12 kA/cm(2) before breakdown. We also demonstrate that nanosecond pulsed output operation of these devices with per pixel onaxis average peak intensity up to 2.9 microW/microm(2) (corresponding to energy of 45pJ per 22ns optical pulse) can be achieved. We investigate the pertinent performance characteristics of these arrays for micro-projection applications, including the prospect of integrated optical pumping of organic semiconductor lasers.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.