Bell System Technical Journal Research Articles

Comparative Additional Factor for Diffraction Loss On (TEM01) Mode from That of (TEM00) Mode

Comparative Additional Factor for Diffraction Loss On (TEM01) Mode from That of (TEM00) Mode

Finite Element Analysis of Miniature Thermoelectric Cooler for the Thermal Management of Si-Based Photonic Integrated Circuits

Today’s electronic and photonic devices are facing a bottleneck in removing and managing the excess heat flux due to its progressive miniaturization and integration density. Generation of high heat flux during device operation has become a major challenge and makes the Si-based photonic integrated circuits (PIC) less efficient to function at the desired temperature. Hence, it is essential to remove/ manage the heat flux to maintain efficient and reliable operation of the device. The state-of-art solution to control device temperature involves macro thermoelectric coolers (TEC), which are inefficient in meeting the thermal management requirement for photonic integrated circuits (PIC). Thermal management of these optoelectronic chips using a micro-thermoelectric coolers (µTECs) can be a better proposition, as it can be integrated directly on the photonic chip by removing the large macro-TECs, which will allow precise control of the thermal load [1]. µTECs integrated with optoelectronic devices (lasers, modulators, etc.) can handle large heat flux, with fast response time and can provide high device performance with reduced cost [2].In this work, a comprehensive study focusing on the cooling performance of the µTECs for a photonic package is performed by finite element method (FEM) using COMSOL Multiphysics software. All the simulations and design optimizations have been done following the microfabrication constraints along with the realistic heat flux scenarios. In order to enable the full potential of silicon-based photonic devices, we considered Si as the substrate. The effect of parameters such as load current, the thickness and shape of the thermoelectric pillars, thickness of the interconnect material and number of thermoelectric pillars on device cooling performance are optimized. It is known that bismuth-telluride (Bi-Te) based thermoelectric materials currently have the highest cooling performance near room temperature. For design optimization, first, a single uni-pair is considered and thermoelectric properties of electrodeposited CuTe and BiSbTe are selected as the n- and p-type thermoelectric materials [3, 4]. Also, the effect of substrate, which significantly influences the heat flow between the µTEC and atmosphere is studied. The results indicate that with increasing the leg height, first ΔT increases and later decreases due to joule heating while the coefficient of performance (COP) decreases. A range of load current (I) between 5 to 450 mA is applied and a maximum temperature difference of around 35 K is achieved at 250 mA. In summary, µTEC can be better choice as opposed to macro-TEC in terms of energy efficiency with the benefit of using less toxic materials, which may pave the way of future highly integrated optoelectronic circuits. Acknowledgments This work received funding from the European Union’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 825114 (SmartVista). This publication has emanated from research supported in part by a research grant from Science Foundation Ireland (SFI) and is co-funded under the European Regional Development Fund under Grant Number 15/IA/3160, 12/RC/2276 and 13/RC/2077 References R. Enright, S. Lei, K. Nolan, I. Mathews, A. Shen, G. Levaufre, R. Frizzell, G. H. Duan and D. Hernon, Bell Labs Technical Journal, 19, 31 (2014). S. Corbett, D. Gautam, S. Lal, K. Yu, N. Balla, G. Cunningham, K. M. Razeeb, R. Enright and D. McCloskey, ACS Applied Materials & Interfaces, 13, 1773 (2021). S. Lal, K. M. Razeeb and D. Gautam, ACS Applied Energy Materials, 3, 3262 (2020). S. Lal, D. Gautam and K. M. Razeeb, APL Materials, 7, 031102 (2019). Figure 1

Entropy vs. human ontogeny: the Shannon information measure; a reliable general indicator of human health?

ABSTRACT A measure of health based on exact sciences is not considered by social sciences to evaluate human development. We propose the H measure of information of Shannon ([1948]. “A Mathematical Theory of Communication.” The Bell Systems Technical Journal 27 (3): 379–423, 623–656), renamed as H cto , as a general indicator of human health which can be subsequently aggregated at any statistical level. Several advantages of H cto are explained: (i) connections with thermodynamics and information theory; (ii) combination of physical and statistical elements; (iii) measurements of entropy and/or information depending on the reference point, and (iv) a collection of examples based on the scientific literature that supports the application of H cto . Simplified graphical models of the ontogeny of health condition are also shown. The empirical feasibility of using H cto is also analysed, by concluding that it could be a tangible reality in the near future.

Metapsychological consequences of the conscious brainstem: A critique of the conscious id

ABSTRACTIn this article, the thesis that the id is conscious [Solms, (2013a) The conscious id. Neuropsychoanalysis, 15(1), 5–19] is scrutinized by carving out a crucial implicit assumption on which the argument relies. The validity of this assumption is then assessed in two ways: first by an analysis of Freud’s description of the relation between the mental apparatus and the brain, second by analyzing the neuropsychoanalytical implications of the Mealy machine [Mealy, 1955. A method for synthesizing sequential circuits. Bell Labs Technical Journal, 34(5), 1045–1079] – a mathematical model that is used to describe the relation between the software and hardware of computers. The result of my assessment is that Solms’s implicit assumption faces serious objections and therefore the conclusion that the id is conscious cannot be upheld. In the remaining article I develop, based on the neuroscientific findings on which Solms developed his thesis [Solms & Panksepp, 2012. The “id” knows more than the “ego” admits: Neuropsychoanalytic and primal consciousness perspectives on the interface between affective and cognitive neuroscience. Brain Sciences, 2(2), 147–175], a concurrent adaptation of the structural model. This is achieved by an analysis of Freud's development of his metapsychological theory from 1899 to 1923, with a strong focus on the conceptualization of consciousness that underwent, as I shall work out, a major change. The result is a new metapsychological model that, so I claim, gets rid of a crucial weak spot of the structural model [Freud, 1923. The ego and the id. Standard Edition, 19, 12–59] and allows the integration of different neuropsychological theories.

How Bizarre: The Glitch of the Nineties as a Fantasy of New Authorship

How Bizarre: The Glitch of the Nineties as a Fantasy of New Authorship

(Invited) Effect of Annealing on Thermoelectric Properties of Electrodeposited Bisbte Films

Thermal management of microelectronics and optoelectronics devices using thermoelectric (TE) coolers is an efficient way for active temperature control, where miniaturization of the devices led to generate a high heat flux, which is difficult to manage1, 2. In this regard, bismuth telluride (Bi-Te) based materials have been extensively studied due to their relatively high thermoelectric efficiency near room temperature regime for the fabrication of thermoelectric devices. Various deposition techniques have been used for the growth of Bi-Te thin films such as sputtering3, metal organic chemical-vapor deposition4, molecular beam epitaxy 5 and electrodeposition6. The use of electrodeposition in synthesis of thermoelectric materials and device is highly recommended due to its suitability in terms of cost effectiveness, up-scalability and ease of controlling material properties such as composition, crystallinity and morphology. Moreover, because of its compatibility with microelectronic processing techniques, electrodeposition can be used to fabricate micro-scale thermoelectric cooler directly on the wafer for thermal management of photonics and electronic devices. But the thermoelectric efficiency of these electrodeposited films is still low. Thermal annealing of electrodeposited film is one of the ways to enhance the TE properties7. The effect of annealing has been examined for different types of thermoelectric films fabricated using different deposition techniques7-9. However, a systematic study of annealing parameters on the electrodeposited p-type BiSbTe film is still missing. Thereby, in this work we have investigated the effect of annealing parameters in enhancing the TE properties of electrodeposited p-type BiSbTe films. The influence of thermal annealing on microstructure and TE properties were investigate within a temperature range of 250 - 400 °C in nitrogen atmosphere. Scanning electron microscopy (Figure 1) and x-ray diffraction techniques were used to study the change in microstructure and crystallinity of the films. Seebeck coefficient and electrical conductivity were measured at room temperature. It was observed that increasing the annealing temperature increased the Seebeck coefficient. A maximum Seebeck coefficient of 94 μV/K and a corresponding power factor of 263.72 µW/mK2 was obtained for the p-type BiSbTe film annealed at 350 °C for 1h. We found that the annealing parameters played a vital role in determining the thermoelectric (TE) properties of the film. Further increase in the annealing temperature led to a decrease in the TE properties due to the depletion of tellurium content in the films. The influence of the annealing parameters on the TE properties for the p-type BiSbTe based electrodeposited films were analyzed in detail with a view to fabricate a complete thermoelectric device. Acknowledgment Authors acknowledge financial support from the European Union’s Horizon2020 funded project “Thermally Integrated Smart Photonics Systems (TIPS)”, under the grant agreement No. 644453. This publication has emanated from research supported in part by a research grant from Science Foundation Ireland (SFI) and is co-funded under the European Regional Development Fund under Grant Number 13/RC/2077. Corresponding author's email addresses: kafil.mahmood@tyndall.ie Reference 1. R. Enright, S. Lei, K. Nolan, I. Mathews, A. Shen, G. Levaufre, R. Frizzell, G. H. Duan, and D. Hernon, Bell Labs Technical Journal, 1931-45 (2014). 2. C. O'Dwyer, R. Chen, J.-H. He, J. Lee, and K. M. Razeeb, ECS Journal of Solid State Science and Technology, 6(3), Y3-Y3 (2017). 3. H. Noro, K. Sato, and H. Kagechika, Journal of Applied Physics, 73(3), 1252-1260 (1993). 4. S.-D. Kwon, B.-k. Ju, S.-J. Yoon, and J.-S. Kim, Journal of Electronic Materials, 38(7), 920-924 (2009). 5. B. Gardes, J. Ameziane, G. Brun, J. C. Tedenac, and A. Boyer, Journal of Materials Science, 29(10), 2751-2753 (1994). 6. S. Lal, D. Gautam, and K. M. Razeeb, ECS Journal of Solid State Science and Technology, 6(3), N3017-N3021 (2017). 7. D. M. Lee, C. H. Lim, D. C. Cho, Y. S. Lee, and C. H. Lee, Journal of Electronic Materials, 35(2), 360 (2006). 8. S.-j. Jeon, M. Oh, H. Jeon, S. Hyun, and H.-j. Lee, Microelectronic Engineering, 88(5), 541-544 (2011). 9. B. Fang, Z. Zeng, X. Yan, and Z. Hu, Journal of Materials Science: Materials in Electronics, 24(4), 1105-1111 (2013). Figure 1. SEM image of electrodeposited BiSbTe films annealed at different temperatures for 1 hour. Figure 1

Guest Editorial Biological Applications of Information Theory in Honor of Claude Shannon’s Centennial—Part 1

Claude Shannon, born on April 30, 1916, pioneered the mathematical theory of communication in his 1948 paper in the Bell System Technical Journal . Information theory has since provided the foundation for the digital revolution in communications technology. In addition, it has provided a powerful framework for investigating the fundamental limitations of naturally occurring communications, particularly in biological systems. This two-part special issue of the IEEE Transactions on Molecular, Biological, and Multi-Scale Communications honors Shannon’s centennial by highlighting recent progress in biological and bio-inspired information theory. Part I includes papers on applications of multivariate mutual information to data clustering, statistical thermodynamics of nonequilibrium chemical processes, information processing in neuronal systems, biochemical signal transduction systems, DNA sequencing, and the swarming of insects.

Existence of bounded discrete steady state solutions of the van Roosbroeck system with monotone Fermi---Dirac statistic functions

If in the classic van Roosbroeck system (Bell Syst Tech J 29:560---607, 1950) the statistic function is modified, the equations can be derived by a variational formulation or just using a generaliz...

Optical networking and technology innovation

Optical networking technologies have evolved significantly over the last few years: 100G coherent has been commercialized; flexibility in data rate, frequency grid and modulation format is a hotly debated topic; energy efficiency is becoming even more important, and tighter integration of the packet and circuit switched world continues to be of highest interest. Since the last Bell Labs Technical Journal (BLTJ) issue devoted to optical systems and networking was published in winter 2010, it seems timely to address these developments in a new BLTJ issue on Optical networking and technology innovation.

Overview

Presents an overview of the articles included in this issue of Bell Labs Technical Journal.

Phreaking out ma bell

Ralph Barclay was walking through the engineering library at Washington State University, just minding his own business, when it called out to him. He couldn't say why, it just did. It was a booklet, about 18 by 23 centimeters and maybe a centimeter thick, on display in the library's new periodicals section. Its pale blue cover proclaimed it to be the November 1960 issue of something called The Bell System Technical Journal. It had been out for less than a week. Barclay looked at the table of contents printed on its cover. Most of the articles could put even the hardest of hard-core geeks to sleep at 20 paces: "Magnetic Latching Relays Using Glass Sealed Contacts," "Molecular Structure in Crystal Aggregates of Linear Polyethylene," or the ever popular "Ionic Radii, Spin-Orbit Coupling, and the Geometrical Stability of Inorganic Complexes."

Modeling of Wide-Band Optical Signal Amplification in an EDFA Network Using Tunable Tap

Optical amplification in C and L band region with wave division multiplexing can provide over 160 channels. The paper provides simulation studies of such a wideband erbium doped fiber amplifier which utilizes a tunable tap at the TLS source end. This isolates and provides two parallel channels for simultaneous amplification in both C and L band. Such a configuration has shown to provide a gain well over 20dB from 1525-1615nm bandwidth with average noise figure of 10dB (approx.). Gain saturation effects beyond -20dBm/channel signal level and, gain spectra at different pump powers and amplifier lengths have also been studied. Full Text: PDF References Robert E. Tench, Proc. IEEE Elecronic Componenets and Technology Conference. 9, (1999). J. F. Massicott, R. Wyatt, and B. J. Ainslie, "Low noise operation of Er 3+ doped silica fibre amplifier around 1.6 ?m", Electron. Lett. 28, 1924 (1992). CrossRef Y. Sun, A. Srivastava, J.Zhou, and J. Sulhoff, "Optical fiber amplifiers for WDM optical networks", Bell Labs Technical Journal. 4, (1999) CrossRef H. Ono, M. Yamada and Y. Ohishi, "Gain-flattened Er/sup 3+/-doped fiber amplifier for a WDM signal in the 1.57-1.60-?m wavelength region", IEEE Photon. Technol. Lett. 9, (1997). CrossRef C. Jiang, W. Hu, Q. Zeng and S. Xiao, "High detectivity GaInAs-InP quantum-well infrared photodetectors grown on Si substrates", IEEE Photon. Technol. Lett. 14, 290 (2002). CrossRef M. A. Mahdi, F. R. M. Adikan, P. Poopalan, S. Selvakennedy, W. Y. Chan, and H. Ahmad, "Long-wavelength EDFA gain enhancement through 1550 nm band signal injection", Opt. Commnun.175, 296 (2000). CrossRef H. Chen, M. Leblanc and G.W. Schinn, "Gain enhanced L-band optical fiber amplifiers and tunable fiber lasers with erbium-doped fibers", Opt. Comm. 216, 119 (2003). CrossRef M. A. Mahdi and H. Ahmad, "Gain enhanced L-band Er/sup 3+/-doped fiber amplifier utilizing unwanted backward ASE", IEEE Photon. Technol. Lett. 13, 1067 (2001). CrossRef S. W. Harun, N. Tamchek, P. Poopalan and H. Ahmad, "Gain clamping in two-stage L-band EDFA using a broadband FBG", IEEE Photon. Technol. Lett. 16, 422 (2004). CrossRef T. Sakamoto. "Wide wavelength band (1535?1560 nm and 1574?1600 nm), 28 × 10 Gbit/s WDM transmission over 320 km dispersion-shifted fibre", Electron. Lett.34, 392 (1998). CrossRef Y. Sun et al., "80 nm ultra-wideband erbium-doped silica fibre amplifier", Electron. Lett. 33,1965 (1997). CrossRef T. Kasamatsu, Y. Tano and T. Ono, 13, 31 (2001). S. K. Liaw and Y. K. Chen, "Self-phase modulation coefficient of multiple-quantum-well optical amplifiers", IEEE Photon. Tech. Lett. 8, 876 (1996). CrossRef A. Srivastava and Y. Sun, Optical Fiber Telecommunications, I. P. Kaminov and T. Li, Eds. (San Diego, CA: Academic 2002, vol. VI A). R. Anthony and S.N. Biswas, "Temperature Dependent Gain Analysis of a Cascaded C-Band EDFA DWDM Network", Elseviers Procedia Technol. 4, 92 (2012). CrossRef G. Luo, J. L. Zyskind, I. A. Nagel, and M. A. Ali, "Experimental and theoretical analysis of relaxation-oscillations and spectral hole burning effects in all-optical gain-clamped EDFA's for WDM networks", IEEE J. Lightwave Technol. 16, 527 (1998). CrossRef I.K. Bu Sohn and J.W. Song, "Gain flattened and improved double-pass two-stage EDFA using microbending long-period fiber gratings", Optical Communications. 236, 141 (2004). CrossRef R. Singh, Sunanda and E.K. Sharma, "Gain flattening by long period gratings in erbium doped fibers", Optical Communications. 240, 123 (2004). CrossRef

Introduction

The increasing role—even preeminence—of the end user in telecommunications today is one of the key trends facing Alcatel-Lucent and the entire telecom industry. This means that technology studies are more and more often driven or provoked by end user requirements, requests, or latent needs. Alcatel-Lucent's answer to this challenge encompasses strategic directions in both application enablement and high leverage network technology. The papers presented in this General Papers issue of the Bell Labs Technical Journal demonstrate how Alcatel-Lucent has integrated that trend at the different technical levels of the communication domain, from end user applications to wireless and optical networks, dealing with technologies related to semantics and interaction, network capabilities, network engineering, security, new access networks, and improvement in access and optical networks.

Entropy, semantic relatedness and proximity

Although word co-occurrences within a document have been demonstrated to be semantically useful, word interactions over a local range have been largely neglected by psychologists due to practical challenges. Shannon's (Bell Systems Technical Journal, 27, 379-423, 623-665, 1948) conceptualization of information theory suggests that these interactions should be useful for understanding communication. Computational advances make an examination of local word-word interactions possible for a large text corpus. We used Brants and Franz's (2006) dataset to generate conditional probabilities for 62,474 word pairs and entropy calculations for 9,917 words in Nelson, McEvoy, and Schreiber's (Behavior Research Methods, Instruments, & Computers, 36, 402-407, 2004) free association norms. Semantic associativity correlated moderately with the probabilities and was stronger when the two words were not adjacent. The number of semantic associates for a word and the entropy of a word were also correlated. Finally, language entropy decreases from 11 bits for single words to 6 bits per word for four-word sequences. The probabilities and entropies discussed here are included in the supplemental materials for the article.

Auld Lang Syne [Microwave Surfing

In July 1922, when the information department of the American Telephone and Telegraph Company (AT&T) printed vol. 1, no. 1 of the now-legendary The Bell System Technical Journal (BSTJ) (US$0.50 per copy; US$1.50 per year), the field of electrical communication was still in its infancy.

Overview

Welcome to the Bell Labs Technical Journal special issue on the Mobile Handset Platform for Service Delivery. The notion of what a mobile phone is and the tasks that it is expected to discharge has undergone a rapid evolution in the past few years. In many ways the evolution of the mobile handset has paralleled our definition of being connected. It is no longer enough to be able to have a real-time verbal conversation. Modern handsets are required to support a wider, richer version of communicating: via social networking sites, Internet video calls, and various textual exchange mechanisms. Add to this personal entertainment: resident and streaming music and video. The handset is also increasingly becoming a mechanism for e-commerce: from traditional web commerce experiences to specialized applications for everything from ordering takeout to paying at a parking meter. With the convergence of 1) high performance low power processors, 2) bright, high resolution screens, 3) the ability to bridge multiple wireless communication technologies, and 4) increasing wireless wide area network (WAN) data coverage, the stage is set for a smart mobile handset—a new device that marries the functions of a traditional PC with that of a mobile phone. The burgeoning capabilities of the modern mobile handset pose a number of opportunities and technical challenges. This issue of the Bell Labs Technical Journal explores a few of the challenges and potential applications for a smart handset and the network infrastructure requirements, such as security, that are needed.

Biological Information—Definitions from a Biological Perspective

The objective of this paper is to analyze the properties of information in general and to define biological information in particular.

Auld Lang Syne [AP-S Turnstile

“Technological innovation” is more than just invention. It is a process, often long and costly, of transforming new scientific knowledge into feasible technology, introducing it to use, and making its benefits available to the public. “Technical integration” is intended to emphasize the more subtle flow of an intangible - engineering information and understanding. Not only has Bell Labs innovated, but it also showed the world technical integration of the innovations. The Bell System Technical Journal was a key enabler for this achievement.

Optical Integrated Circuits: A Personal Perspective

<para xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> The remarkable early success and current explosive growth of electronic integrated circuits have fascinated photonics researchers since 1969 with the prospect of similar success in optical integrated circuits. Alas, physical and economic factors have stymied their efforts. Two recent commercial optical integrated circuits may be the first points on a photonic Moore's law curve. The author presents his view of the progress of optical integrated circuits since S. E. Miller's proposal in the 1969 <emphasis emphasistype="boldital">Bell Systems Technical Journal</emphasis>. </para>

Does Norwich's Entropy Theory of Perception avoid the use of mechanisms, as required of an information-theoretic model of auditory primary-afferent firing

Norwich et al.'s Entropy Theory (1975-present) stipulates that (1) the auditory receptor is uncertain about the stimulus' intensity, (2) uncertainty, given by the “entropy” H, relates to primary afferent neuronal firing-rate F as F=constant×H. H was calculated according to Garner &amp; Hake (Psychological Review 58, 1951; after Shannon, Bell System Technical Journal 27, 1948) using Information Theory. H is available any time events, their outcomes, and the appropriate probabilities of occurrence are known, precisely because Information Theory ignores mechanisms, such as sensory transduction. Hence, any “information-theoretic” hearing model must avoid physiological mechanisms, and Norwich et al. claim to comply. But do they? The Entropy Theory was scrutinized for avoidance of physiological mechanisms. Norwich et al. stipulated throughout that (1) “We can envisage a steady sensory stimulus as a stationary stochastic sequence of microscopic sensory events” (Norwich &amp; Wong, Annales de la Fondation Louis de Broglie 22, 1997), (2) those events (representing different intensities) are repeatedly sampled by the receptor. Sampling is a mechanism, not separable from transduction, the event's (presumed) “outcome”. Also, Norwich et al.'s attempts to separate events from outcomes produces inconsistent identification of “events.” The Entropy Theory is not an information-theoretic model of primary-afferent firing.