The silicon photonic crystal used in the JNCASR work was patterned to mimic the lattice of which material?
- A.Diamond
- B.Graphene
- C.Gallium nitride
- D.Sapphire
Correct answer
Explanation
The correct answer is graphene. The team designed a silicon photonic crystal whose structure mimics the honeycomb lattice of graphene, arranging triangular holes in a silicon slab so that terahertz waves travel along the boundary between two regions of the crystal. A barrier was then created by changing the sizes of those triangular holes over a short section of the waveguide, and the waves still crossed it with only about one to two per cent loss, rising to roughly two to three per cent for two barriers in sequence. Options A, C and D name diamond, gallium nitride and sapphire, which are important materials in electronics and optics but are not the lattice imitated here. The devices were fabricated on high-resistivity silicon, which is compatible with established semiconductor manufacturing lines.
Read the full article: JNCASR Silicon Chip Carries Terahertz Data at 100 Gbit/s
Practice Questions
Which institute developed the silicon chip that carried terahertz data at 100 Gbit/s across an engineered barrier?
- A.Indian Institute of Science, Bengaluru
- B.Jawaharlal Nehru Centre for Advanced Scientific Research
- C.Saha Institute of Nuclear Physics, Kolkata
- D.Centre for Development of Telematics
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Its team, led by Dr Abhishek Kumar of the Meta Optics Laboratory, used topological photonics to show terahertz waves crossing a deliberately engineered barrier while carrying data at 100 Gbit/s, with the work published in the journal Advanced Materials.
Read the full explanation →Over which frequency range were the JNCASR terahertz devices measured?
- A.24 to 40 GHz
- B.110 to 170 GHz
- C.310 to 360 GHz
- D.600 to 750 GHz
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Measurements across this band agreed closely with the simulations the team had run, and in the power splitter the two output signals were nearly identical, showing that the engineered barrier had little effect on transmission.
Read the full explanation →Which principle did Dr Jitendra Singh propose as the guide for Indo-Pacific cooperation in ocean science?
- A.One Ocean, Shared Knowledge and Equitable Prosperity
- B.One Earth, One Family, One Future
- C.Security and Growth for All in the Region
- D.Blue Economy for Shared Wealth
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The Minister offered this as the principle that should steer cooperation across the Indo-Pacific, arguing that oceans ignore political boundaries and that marine pollution or a change in ocean temperature has effects far beyond the country where it begins.
Read the full explanation →How many aquanauts is the Matsya submersible designed to carry?
- A.Two
- B.Three
- C.Four
- D.Six
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The submersible of the Samudrayaan Mission is built to take three aquanauts down to depths between five and six thousand metres, and it is the vehicle behind the plan for a crewed Indian dive later this decade.
Read the full explanation →According to Dr Jitendra Singh at IPRD 2026, by which year will India send its first human deep-sea mission to a depth of up to 6,000 metres?
- A.2026
- B.2027
- C.2028
- D.2030
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The Minister said India is progressing towards sending its first crewed deep-sea mission to a depth of as much as six thousand metres by that year, which he called an important milestone in an exploration programme built on indigenous capability.
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