Fabrication of 32 Gb/s Electroabsorption Modulated Distributed Feedback Lasers by Selective Area Growth Technology

A 32 Gb/s monolithically integrated electroabsorption modulated laser is fabricated by selective area growth technology. The threshold current of the device is below 13mA. The output power exceeds 10mW at 0V bias when the injection current of the distributed feedback laser is 100mA at 25℃. The side mode suppression ratio is over 50 dB. A 32Gb/s eye diagram is measured with a 3.SVpp nonreturn-to-zero pseudorandom modulation signal at -2.3 V bias. A clearly opening eyediagram with a dynamic extinction ratio of 8.01 dB is obtained.

COVID-19 and Learning Styles: GCET as Case Study

The COVID-19 pandemic has caused higher educational institutions around the world to close campus-based activities and move to online delivery.The aim of this paper is to present the case of Global College of Engineering and Technology(GCET)and how its practices including teaching,students/staff support,assessments,and exam policies were affected.The paper investigates the mediating role of no detriment policy impact on students’result along with the challenges faced by the higher educational institution,recommendations and suggestions.The investigation concludes that the strategies adopted for online delivery,student support,assessments and exam policies have helped students to effectively cope with the teaching and learning challenges posed by the COVID-19 pandemic without affecting their academic results.The study shows that 99%of students were able to maintain the same or better level of performance during the 1st COVID-19 semester.One percent of students had shown a slight decrease in their performance(about 1%–2%)with respect to their overall marks pre-COVID-19.The no detriment policy has succoured those 1%of the students to maintain their overall performance to what it used to be pre-COVID-19 pandemic.Finally,the paper provides the list of challenges and suggestions for smooth conduction of online education.

Research Progress of Two-d imensional Matrix Detectors in IMRT Dose Verification

With the continuous development of science and technolog ies in China,radiotherapy technology in medical field has been very significant ly developing,and intensity modulated radiation therapy(IMRT)technology has been the most widely used.This paper first introduces the components and types of two-dimensional matrix detector,two-dimensional ionization chamber matrix detector and two-dimensional semiconductor matrix detector,then analyzes the dosimetric characteristics of the two-dimensional matrix detector.In the end,the various applications of the two-dimensional matrix detector are analyzed and discussed in detail.The paper aims to promote the two-dimensional matrix detector’s development in the field of radiotherapy in China.

A 1.2-V,84-dB∑△ADM in 0.18-μm digital CMOS technology

A low power and low voltage∑△analog-to-digital modulator is realized with digital CMOS technology, which is due to full compensated depletion mode capacitors.Compared with mixed signal technology,this type of modulator is more compatible for pure digital applications.A pseudo-two-stage class-AB OTA is used in switchedcapacitor integrators for low voltage and low power.The modulator is realized in standard SMIC 0.18μm 1P6M digital CMOS technology.Measured results show that with 1.2 V supply voltage and a 6 MHz sample clock,the dynamic range of the modulator is 84 dB and the total power dissipation is 2460μW.