The rise of computers in past decades was made possible largely thanks to the invention of the integrated circuit, a device that combines all necessary electronic components onto a single chip. In a similar vein, the success of optical computing is largely dependent on the possibility of integrating all essential optical components onto a single chip (photonic circuit). Lim Teck Guan at the A*STAR Institute of Microelectronics and co-workers have now developed an enhanced alignment solution for photonic circuits. “Our approach offers a highly accurate, passive optical alignment solution for these devices,” says Guan.
The fabrication of photonic circuits is no easy task because there is little room for error. In order to get the best performance from these devices operating at the visible or near-infrared spectrum, various elements must be aligned with utmost precision, typically within an error of around one micrometer. Even with the slightest misalignment, a microlens, for example, might not be able to focus light into a photodetector.
The researchers came up with an alignment method that is remarkably straightforward and easy to implement. It is based on a circular through-hole with two diameters. The design of the larger hole is not critical and it can either partially or entirely accomodate the spherical lens, depending on the application requirement. A second hole in the chip is smaller than the sphere diameter so that if the lens is pressed against the opening the sphere will automatically be aligned in its center. In this way, light from underneath the chip is guided through the lens and the second hole, and on to a photodetector that is placed directly above.
This guided assembly scheme makes it easy to fabricate more complex photonic circuits, once the spherical lenses are integrated with the layer containing the through-holes. Electronic circuits of virtually any complexity can be placed on the chip with high accuracy, so that they align perfectly with the optical beam shone through the lens. The measured efficiencies of the light coupling between the different components on the chip are promising and demonstrate light propagation with few losses.
In the current assembly, a laser is placed on a chip and through a combination of mirrors and microsphere lenses, the light is guided across the chip to a photodetector. However, the researchers have already set their sights on the advantages of further integration. “In future, we might come up with more complex circuits,” suggests Guan. “These devices could lead to applications including high-speed, high-bandwidth integrated photonic circuits, particularly if we can integrate conventional silicon electronics with photonic functionality.”
Guan, L. T. et al. Integrated optical carrier for optical/electrical interconnect. IEEE Transactions on Components, Packaging, and Manufacturing Technology 1, 125–132 (2011).
Fraunhofer ISE Supports Market Development of Solar Thermal Power Plants in the MENA Region
21.02.2018 | Fraunhofer-Institut für Solare Energiesysteme ISE
New tech for commercial Lithium-ion batteries finds they can be charged 5 times fast
20.02.2018 | University of Warwick
A newly developed laser technology has enabled physicists in the Laboratory for Attosecond Physics (jointly run by LMU Munich and the Max Planck Institute of Quantum Optics) to generate attosecond bursts of high-energy photons of unprecedented intensity. This has made it possible to observe the interaction of multiple photons in a single such pulse with electrons in the inner orbital shell of an atom.
In order to observe the ultrafast electron motion in the inner shells of atoms with short light pulses, the pulses must not only be ultrashort, but very...
A group of researchers led by Andrea Cavalleri at the Max Planck Institute for Structure and Dynamics of Matter (MPSD) in Hamburg has demonstrated a new method enabling precise measurements of the interatomic forces that hold crystalline solids together. The paper Probing the Interatomic Potential of Solids by Strong-Field Nonlinear Phononics, published online in Nature, explains how a terahertz-frequency laser pulse can drive very large deformations of the crystal.
By measuring the highly unusual atomic trajectories under extreme electromagnetic transients, the MPSD group could reconstruct how rigid the atomic bonds are...
Quantum computers may one day solve algorithmic problems which even the biggest supercomputers today can’t manage. But how do you test a quantum computer to...
For the first time, a team of researchers at the Max-Planck Institute (MPI) for Polymer Research in Mainz, Germany, has succeeded in making an integrated circuit (IC) from just a monolayer of a semiconducting polymer via a bottom-up, self-assembly approach.
In the self-assembly process, the semiconducting polymer arranges itself into an ordered monolayer in a transistor. The transistors are binary switches used...
Breakthrough provides a new concept of the design of molecular motors, sensors and electricity generators at nanoscale
Researchers from the Institute of Organic Chemistry and Biochemistry of the CAS (IOCB Prague), Institute of Physics of the CAS (IP CAS) and Palacký University...
15.02.2018 | Event News
13.02.2018 | Event News
12.02.2018 | Event News
23.02.2018 | Physics and Astronomy
23.02.2018 | Health and Medicine
23.02.2018 | Physics and Astronomy