Optoelectronic integrated circuits utilising vertical-cavity surface-emitting semiconductor lasers

Abstract

We use two-colour vibronic coherence spectroscopy to observe long-lived vibrational coherences in the ground electronic state of carotenoid molecules, with decoherence times in excess of 1 ps. Lycopene and spheroidene were studied isolated in solution, and within the LH2 light-harvesting complex extracted from purple bacteria. The vibrational coherence time is shown to increase significantly for the carotenoid in the complex, providing further support to previous assertions that long-lived electronic coherences in lightharvesting complexes are facilitated by in-phase motion of the chromophores and surrounding proteins. Using this technique, we are also able to follow the evolution of excited state coherences and find that for carotenoids in the lightharvesting complex the S 2 |S 0 superposition remains coherent for more than 70 fs. In addition to the implications of this long electronic decoherence time, the extended coherence allows us to observe the evolution of the excited state wavepacket. These experiments reveal an enhancement of the vibronic coupling to the first vibrational level of the C-C stretching mode and/or methyl-rocking mode in the ground electronic state 70 fs after the initial excitation. These observations open the door to future experiments and modelling that may be able to resolve the relaxation dynamics of carotenoids in solution and in natural light-harvesting systems.

<title>Optical performing the operation of matrix multiplication on the base of waveguide microring resonators</title>

“…The time of performing of matrix multiplication consists of the time interval of radiation propagation through the input and output waveguides of the microresonator array, which is defined by the dimension of multiplied matrix, the time of resonator transmittance switching and signal reading by photodetector. For modern photodetectors the signal reading time could be as short as 0.01-0.1 ns [3][4][5]. The time of switching microresonator transmittance doesn't exceed 20-40 ps [7].…”

“…Speed of electronics components performing matrix calculations is insufficient for many modern applications. The known optical matrix processors base on the use of fiber optics [1,2] and 2D transparencies with arrays of emitters and photodetectors [3][4][5]. Thus it is difficult to produce them using the integrated technology.…”

Heterogeneously Integrated Optoelectronic Devices Enabled by Micro‐Transfer Printing

“…Semiconductor diode lasers based on III–V epitaxial materials are widely used in optical communication systems, laser printers, barcode readers, CD/DVD players, as well as biomedical imaging devices and sensors . Significant interest exists in the heterogeneous integration of such directional, coherent light emitters with dissimilar classes of materials and devices . For example, light sources represent essential components for silicon‐based integrated photonic circuits for on‐chip communications .…”

“…Significant interest exists in the heterogeneous integration of such directional, coherent light emitters with dissimilar classes of materials and devices . For example, light sources represent essential components for silicon‐based integrated photonic circuits for on‐chip communications . Despite clever schemes for inducing light emission directly from the silicon itself and for hybrid integration by heteroepitaxy, and wafer bonding, deficiencies in operating efficiencies, constraints associated with materials compatibility and complex processing requirements remain.…”

Single Wafer Atomic Layer Deposition Reactor Design

“…It was applied in thin film electroluminescence (TFEL) [2] flat displays and photonics [3] in the early time. Since 1990s, with the need of smaller semiconductor devices [4] and the development of integrated circuits [5], ALD has received more and more attentions for its accurate sub-nanometer thickness control as well as superior uniformity and conformal coating. As a consequence, this technique has been applied in relevant industries [6,7].…”