Nanoscale accurate heterogeneous integration of waveguide devices by transfer printing

The vertical micro-assembly of membrane photonic devices across a range of materials is presented, including polymers, silicon and III-V semiconductors. Fully-fabricated waveguide structures are integrated with sub-100nm absolute placement accuracy. Light-emitting diodes, silicon photonics and nanowire lasers are examples of the deployment of this technique

Hybrid integration of an evanescently coupled AlGaAs micro-disk resonator with a silicon waveguide by nanoscale-accurate transfer printing

Hybrid integration of a III-V micro-disk resonator on a silicon-on-insulator waveguide platform is demonstrated. Transfer printing with nanoscale accuracy is used to micro-assemble an evanescently coupled all-pass micro-disk resonator, with a targeted coupler gap of 100 nm using pre-fabricated AlGaAs and silicon components. Transmission measurements show hybrid resonances with a loaded Q-factor of 7x103 and cavity finesse of over 100

Integrated AlGaAs Devices for Non-linear Applications

The heterogeneous integration of AlGaAs-on-insulator has great potential for nonlinear optics. This talk will explore chip-scale bonding and transfer printing techniques for the development of integrated photonic chips for second- and third-order non-linear applications

Integrated Nonlinear Photonics in AlGaAs-on-insulator Devices

The heterogeneous integration of AlGaAs-on-insulator (AlGaAs-OI) has proven to be a powerful material platform for nonlinear optics. This talk will explore how chip-scale bonding and transfer printing techniques can be used for the fabrication of these integrated photonic chips for highly efficient second- and third-order non-linear applications

To what extent is behaviour a problem in English schools?:Exploring the scale and prevalence of deficits in classroom climate

The working atmosphere in the classroom is an important variable in the process of education in schools, with several studies suggesting that classroom climate is an important influence on pupil attainment. There are wide differences in the extent to which classroom climate is considered to be a problem in English schools. Some ‘official’ reports suggest that behaviour in schools is ‘satisfactory or better’ in the vast majority of schools; other sources have pointed to behaviour being a serious and widespread problem. The paper details four studies conducted over the past decade which aimed to explore these disparities. The aim of the research was to gain a more accurate insight into the extent to which deficits in classroom climate limit educational attainment and equality of educational opportunity in English schools. The findings question the suggestion that behaviour is satisfactory or better in 99.7% of English schools and the concluding section suggests ways in which deficits in classroom climate might be addressed. Although the study is limited to classrooms in England, OECD studies suggest that deficits in the working atmosphere in classrooms occur in many countries. The study therefore has potential relevance for education systems in other countries

Automated nanoscale absolute accuracy alignment system for transfer printing

The heterogeneous integration of micro- and nanoscale devices with on-chip circuits and waveguide platforms is a key enabling technology, with wide-ranging applications in areas including telecommunications, quantum information processing, and sensing. Pick and place integration with absolute positional accuracy at the nanoscale has been previously demonstrated for single proof-of-principle devices. However, to enable scaling of this technology for realization of multielement systems or high throughput manufacturing, the integration process must be compatible with automation while retaining nanoscale accuracy. In this work, an automated transfer printing process is realized by using a simple optical microscope, computer vision, and high accuracy translational stage system. Automatic alignment using a cross-correlation image processing method demonstrates absolute positional accuracy of transfer with an average offset of <40 nm (3σ < 390 nm) for serial device integration of both thin film silicon membranes and single nanowire devices. Parallel transfer of devices across a 2 × 2 mm2 area is demonstrated with an average offset of <30 nm (3σ < 705 nm). Rotational accuracy better than 45 mrad is achieved for all device variants. Devices can be selected and placed with high accuracy on a target substrate, both from lithographically defined positions on their native substrate or from a randomly distributed population. These demonstrations pave the way for future scalable manufacturing of heterogeneously integrated chip systems

Spatially dense integration of micron-scale devices from multiple materials on a single chip via transfer-printing

The heterogeneous integration of devices from multiple material platforms onto a single chip is demonstrated using a transfer-printing (TP) technique. Serial printing of devices in spatially dense arrangements requires that subsequent processes do not disturb previously printed components, even in the case where the print head is in contact with those devices. In this manuscript we show the deterministic integration of components within a footprint of the order of the device size, including AlGaAs, diamond and GaN waveguide resonators integrated onto a single chip. Serial integration of semiconductor nanowire (NW) using GaAs/AlGaAs and InP lasers is also demonstrated with device to device spacing in the 1 μm range