All-optical switching using nonlinear subwavelength Mach-Zehnder on silicon

We report on the experimental demonstration of ultrafast all-optical switching and wavelength down-conversion based on a novel nonlinear Mach-Zehnder interferometer with subwavelength grating and wire waveguides. Unlike other periodic waveguides such as line-defects in a 2D photonic crystal lattice, a subwavelength grating waveguide confines the light as a conventional index-guided structure and does not exhibit optically resonant behaviour. Since the device had no dedicated port to input optical signal to control switching a new approach was also implemented for all-optical switching control

Determinants of Secondary School Learners Performance in Christian Religious Education in Lelan Sub County, Kenya

In Kenya, Christian Religious Education is taught and examined by the Kenya National Examinations Council in the Kenya Certificate of Secondary Education at the end of the four years of Secondary Education cycle. The teaching of this subject in Secondary Schools ensures that learners are offered an opportunity to develop morally and spiritually (Education Act, 2011). Christian Religious Education was earlier on examined with Social Education and Ethics as rival and complementary subjects.  But, as years went by, the students’ performance in Christian Religious Education declined. This rivalry necessitated the need to investigate students’ performance in Christian Religious Education in Kenya Certificate of Secondary Education in Lelan Division of West Pokot County.  Five objectives and a corresponding number of null hypotheses were adopted.  The Stratified sampling technique was employed to select two hundred and four (204); students, teachers, head teachers and a response rate of two hundred (200). Descriptive and inferential statistics were used to analyze the data. It was established that students’ poor performance in Christian Religious Education was influenced by; the teaching of Social Education and Ethics (SEE), student –teacher relationship, students’ self determination, adequacy of resources, teachers’ and students’ attitudes towards Christian Religious Education besides the extent of teacher involvement in marking Kenya Certificate of Secondary Examination examinations.   The study recommended in- service training for Christian Religious Education teachers, construction of cost effective day secondary schools,   Kenya National Examinations Council’s involvement of teachers in marking Christian Religious Education and elimination of Social Education and Ethics as an examinable subject. Keywords: Kenya Certificate of Secondary Education, performance, attitudes, Christian   Religious Education, Social Education and Ethic

Impact of Selected Constituency Development Fund Activities on Education Development in Likuyani Constituency, Kenya

The purpose of the study was to determine the impact of selected Constituency Development Fund activities on education development in Likuyani Constituency. The study set out to achieve the following objectives: To establish how Constituency Development Fund has been used to facilitate the provision of physical facilities in public secondary schools in Likuyani constituency and to determine the influence of the fund on leaners’ retention.The study used descriptive survey research design and simple random sampling technique. A sample size of ten (10) public secondary schools out of twenty four (24) schools was selected where ninety seven (97) respondents from students, teachers, headteachers and education officers provided data upon which the findings are based.  Information was collected using Questionnaire and interview schedule. Instrument validity and reliability was determined through pilot study. Descriptive statistics was used to analyse and interpret data. The main findings of the study based on each of the research questions were as follows: Regarding the extent of CDF funded physical facilities in public secondary schools, it was found out  that the projects which most benefited from CDF funds were the school land 4 (50%), science laboratory 3(37.5) and computer laboratory 3 (37.5%).The study also established that learners’  retention and rates increased after the introduction of CDF fund although it was still below the expectation with all schools enrolling between 150-200 students ten years down the line and an average completion rate of 69%.Based on the foregoing findings, several conclusions and recommendations  were arrived at: First, CDF funds have helped to facilitate the provision of physical facilities in public secondary schools in Likuyani Constituency to a small extent, 46.7% although the facilities were still not enough. Secondly, the number of learners’ retention rate had significantly gone up with the introduction of CDF. The study recommended that the government should allocate enough funds to ensure that facilities constructed are enough and well equipped. Secondly, the government should increase funds allocated to CDF bursary so that learners’ can fully pay school fee thus increasing the retention and completion rates of students. Keywords: Constituency Development Fund, education development, impact, physical facilities, public secondary education, enrolment, retention and completion

High performance and small footprint spot size converters based on SWG metamaterial lenses

Spot size converters with high expansion ratio are required in a variety of situations. This is the case of non-focusing Silicon on Insulator (SOI) fiber-to-chip grating couplers, which typically require long adiabatic tapers (Ltaper >100μm) from the narrow single-mode waveguides (WSi-wire ~ 500nm) to the wide grating region (Wgrating ~ 15μm). Here, we explore the potential of subwavelength grating (SWG) dielectric metamaterials to implement integrated GRaded INdex (GRIN) lenses to expand the mode field. Our designs achieve the desired Beam Expansion (BE) with insertion losses below 1dB over a distance of only LBE ~ 17μm.Ministerio de Economía y Competitividad, Programa Estatal de Investigación, Desarrollo e Innovación Orientada a los Retos de la Sociedad (cofinanciado FEDER), (TEC2016-80718-R); Universidad de Málaga. Ministerio de Educación, Cultura y Deporte (MECD) (FPU16/06121); Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Diffractive sidewall grating coupler: towards 2D free-space optics on chip.

Silicon photonics has been the subject of intense research efforts. In order to implement complex integrated silicon photonic devices and systems, a wide range of robust building blocks is needed. Waveguide couplers are fundamental devices in integrated optics, enabling different functionalities such as power dividers, spot-size converters, coherent hybrids and fiber-chip coupling interfaces, to name a few. In this work we propose a new type of nanophotonic coupler based on sidewall grating (SIGRA) concept. SIGRAs have been used in the Bragg regime, for filtering applications, as well as in the sub-wavelength regime in multimode interference (MMI) couplers. However, the use of SIGRAs in the radiation regime has been very limited. Specifically, a coarse wavelength division multiplexer was proposed and experimentally validated. In this work we study the use of SIGRAs in the diffractive regime as a mean to couple the light between a silicon wire waveguide mode and a continuum of slab waveguide modes. We also propose an original technique for designing SIGRA based couplers, enabling the synthesis of arbitrary radiation field profile by Floquet- Bloch analysis of individual diffracting elements while substantially alleviating computational load. Results are further validated by 3D FDTD simulations which confirm that the radiated field profile closely matches the target design field.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Influence of Selected Parental and School Location Factors on Learners’ Academic Achievement in Public Day Secondary Schools in Trans - Nzoia and West Pokot Counties, Kenya

Globally, parental and school location factors are perceived to influence learners’ academic achievement as indicated by on-going Curriculum Implementation debate in the Twenty First Century. The debate has led national as well as local scholars to focus on improvement of academic achievement among learners in different categories of schools. The study sought to establish the influence of parental socio-economic and school location factors on learners’ academic achievement. The target population comprises 2,830 respondents from which a sample size of 384 learners, 109 teachers were selected. Ex-post facto and co-relational designs were employed. Questionnaires for learners and teachers, an interview schedule for head teachers, and a document analysis guide were used to collect data. Instruments’ reliability was established through the split-half technique, yielding reliability coefficients of 0.8 and 0.75 for learners’ and teachers’ questionnaire instruments respectively. The validity of the questionnaire instrument was established through a pre-test. Descriptive and inferential statistics using Chi-Square interactive were used to analyse data. The study findings revealed that learners whose parents had higher education were likely to provide adequate academic support service to their children unlike those who were less educated. There was a positive correlation between parental socio- economic status and day school learners’ academic achievement. The study recommended that parents be sensitized on their role in providing adequate facilitation for learners while at home through provision of relevant learning resources, revision materials and by providing transport for learners in day secondary schools. Keywords: Parental and School Location Factors, Academic Achievement DOI: 10.7176/JEP/13-21-05 Publication date:June 30th 202

Teacher Motivational Strategies on Students’ Academic Performance in Day Secondary Schools in Saboti Sub-County,

Teachers motivation has become an important issue given their responsibility to impart knowledge and skills to learners. Consequently, the purpose of this study was to investigate the influence of teacher motivation strategies on the students’ performance in day secondary schools of Saboti Sub-County, Trans Nzoia County, Kenya. Specifically, the study sought to establish how staff development, recognition, advancement and incentives influence students’ academic performance in day secondary schools.  This study was conducted in 20 day secondary schools. The study was limited to the information the respondents gave. Simple stratified sampling technique was used for sampling with each stratum being represented by a sample size using the Kreijcie and Morgan table of sample determination.The data collection instrument was the questionnaire which was tested for validity and reliability before being used in the study. Structured questionnaires were administered to the teachers and head teachers of the day secondary schools in Saboti Sub-County. Data was analyzed using Statistical Package for Social Science (SPSS).The findings of the study were that most teachers lacked motivation in their work and this accounts for the low performance in these schools. Motivation strategies such as recognition, training and development, incentives and career advancement were minimal in the schools. The study recommends that a variety of motivational strategies be consistently employed by the Teachers Services Commission to enhance teachers’ morale and subsequently students’ academic performance. Keywords: Teacher, Motivational Strategy, Students, Academic Performance DOI: 10.7176/JEP/14-12-01 Publication date: April 30th 202

Influence of Institutional Characteristics on Learners’ Academic Achievement in Selected Public Day Secondary Schools in Kenya

Rapid growth in Education as an investment has necessitated and heightened interest in the determination of institutional influence on Learners’ Academic Achievement in Kenya. This is observed in regular Curriculum reforms in the recent past to align the curriculum to learners’ academic aspirations. This study sought to determine the extent to which teachers’ characteristics and teaching learning resources influence students’ academic achievement as measured by the Mean Kenya Certificate of Secondary Education Examination score and grade. The sample size of 109 Teachers and 384 Learners was obtained from the targeted population of 2830 people. Ex-post Facto Design and Correlational Design were adopted in the investigation. Questionnaires for teachers and learners, interviews schedule and document analysis were utilized to gather data. The Questionnaire instrument reliability co–efficient of 0.8 for Teachers and 0.75 for Learners was obtained following a pre-test based on split half technique. Inferential and Descriptive statistics using Chi square interactive facilitated data analysis. The study showed that favourable institutional factors positively correlates with learners’ academic achievement and vice versa. The study recommended that Day school learning facilities and teacher-student ratio be improved as this will facilitate attainment of a higher mean score by learners in the Kenya Certificate of Secondary Education Examinations. Keywords: Institutional Characteristics, Students’ Academic Achievement. DOI: 10.7176/JEP/14-3-06 Publication date: January 31st 202

Influence of Teacher Preparation for Instruction and Educational Resource Provision on Students’ Academic Achievement in Public Day Secondary Schools in Chesumei Sub-County Nandi County Kenya

Curriculum leadership in its entirety plays a vital role in academic achievement in educational institutions. However, majority of studies show that administrators have insignificant impact on learners’ academic achievement. This is not the case since school principals are curriculum leaders and are responsible for learners’ performance in many ways. This study investigated the influence of curriculum leadership on learners' academic achievement in public day secondary schools in Chesumei Sub-County, Kenya. The research focused on two specific objectives: (1) examining the influence of teacher preparation for instruction on students' academic achievements and (2) exploring the influence of educational resources’ provision on students' academic achievement The study drew theoretical inspiration from Fielder's contingency theory, which posits that a leader's efficacy is determined by the alignment between their dominant traits and the situational context. To accomplish these objectives, the researcher employed a descriptive survey research design, offering a comprehensive understanding of the current state of curriculum leadership and its impact on academic achievement. The target population was from 19day schools in Chesumei. Pilot study was conducted in two schools. The study utilized purposive sampling, whereby 17 principals, 17 deputies, 17 director of studies and 85 heads of departments were sampled.  Random sampling technique was used to select a representative sample from the 10 % of form four students in each day school in Chesumei Sub-County. There were no adequate textbooks for all subjects in the school which had negatively affected learners’ academic achievement. The study concluded that teacher preparation and educational resource provision enhances students’ academic achievement. Schools should have adequate textbooks for all subjects, enough laboratories, enough teachers and adequate number of classrooms. The findings from this research Endeavour may provide valuable insights into the dynamics of curriculum leadership in the context of Kenyan public day secondary schools. It is expected that the results may aid educational policymakers, school administrators, and teachers in refining strategies and practices to enhance students' academic achievement, consequently contributing to the overall improvement of the education system in Chesumei Sub-County and Kenya at large