The document discusses recent trends in photonic devices. It begins by defining optics and photonics, and describes some applications of photonics including information technology, healthcare, sensing, lighting and displays. It then explains that photonic devices manipulate or detect light, providing examples like lasers, LEDs and solar cells. The document goes on to discuss latest trends like nanophotonics using graphene, carbon nanotubes and photonic crystals. It also covers silicon photonic devices using silicon-germanium transistors and germanium-tin phototransistors. In conclusion, it predicts future applications of photonics in areas like e-paper, solar panels and light-emitting fabrics.

1. ANKIT KUMAR PANDEY
ELECTRONICS & COMM. ENGG.
NIT DELHI
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2.  Introduction
 Photonics areas
 What are photonic devices?
 What drives the application of photonic devices?
 Latest Trends in Photonic Devices
 Conclusions
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3.  Optics:
• Properties of light and its interaction with matter
• Construction of instruments that use or detect it
 Photonics:
• Use of radiant energy (such as light): photon
• Photonics - photon ↔ Electronics - electron
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4.  Strength: Interdisciplinary nature
 Examples:
• Information Technology and Telecommunications
• Health Care and Life Sciences – Biophotonics
• Photonic Sensing and detection
• Lighting, Energy, and Displays
• In various manufacturing processes
• Security and Defence
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5.  Photonic devices are components for creating,
manipulating, or detecting light
 Includes:
• laser diodes
• LEDs
• Solar and photovoltaic cells
• displays and optical amplifiers.
 Other examples include devices for:
• Modulating a beam of light
• Combining/separating light beams of different wavelength
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6.  Bandwidth , fast data processing and transfer.
 Contactless measuring characteristics.
 Processing possibilities of materials.
 Energy saving.
 Cost and dimension reduction.
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7. 1.Nanophotonics
• Study of the behaviour of light on the nanometer scale
• Interaction of nanometer-scale objects with light
Ex; 4th century Roman glass cage cup(Lycurgus Cup).
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Fig.1 Lycurgus Cup
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8.  Natural examples of Nanophotonics-
• ZnO nanoparticles in Peacock’s feathers
• Photoreceptor rhodopsin
Fig.2. ZnO nanoparticles in Peacock’s feathers
Fig.3 Photoreceptor rhodopsin
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9. 1.1 Graphene based photonic devices
Graphene- a 2-D one-atom-thick planar sheet of carbon
atoms densely packed in a honeycomb crystal lattice.
Fig.4. Graphene lattice
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Nanophotonics
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10.  Graphene Properties
• High mobility
• Optical transparency
• Flexibility
• Robustness and environmental stability.
 Graphene based solar cells and light-emitting
devices ,touch screens, photodetectors and ultrafast
lasers are being developed.[1]
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[1] F. Bonaccorso, Z. Sun, T. Hasan, and a. C. Ferrari, “Graphene Photonics
and Optoelectronics,” vol. 622, no. August 2010, pp. 1–26, 2010.
Graphene based photonic devices
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12. 1.2 Carbon nanotubes (CNT) based photonic devices-
 CNTs - allotropes of carbon with a cylindrical nanostructure
 Advantages of CNT-based photonics devices:
• Ultrafast response
• Robustness
• Tunability of wavelength
• Compatibility to fibers.
Fig.5 Carbon Nanotube
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Nanophotonics
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13. 1.3 Photonic crystals
• Periodic optical nanostructures
• Affect the motion of photons ionic lattices affect
electrons in solids.
• The first commercial products involving 2-D periodic photonic
crystals -photonic crystal fibers.
Fig.6 Photonic crystals in butterfly wings
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Nanophotonics
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14. Photonic crystals
 Band gap forbids certain frequency range.
 Enables to control light not possible with
conventional optics.
 Applications of photonic crystals
• Nanoscopic lasers
• Light emitting diodes
• Photonic integrated circuits
• RF-antennas, reflectors
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15. 1.4 Nanoplasmonics:
• A plasmon is
a quantum of plasma
oscillation
• The resultant of the two
forces (i.e., attractive
driving force and repulsive
restoring force) set up the
longitudinal oscillations
among the free electrons.[2]
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[2] A.K. Sharma, R. Jha, and B. Gupta, “Fiber-Optic Sensors Based on Surface Plasmon Resonance: A
Comprehensive Review,” Sensors Journal, IEEE, vol. 7, no. 8, pp. 1118–1129, 2007.
Fig. 7. Exponential decay of field intensity
of surface plasmon mode in a metal and
dielectric system.
Nanophotonics
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16. 2. Silicon Photonic devices:
Silicon photonics - silicon as an optical medium.
Material benefits provided by silicon:[3]
 Photonic: wide band infrared transparency
 Electronic: low noise, high speed integrated circuits
 Thermal: high heat conductance
 Structural: rugged 3-D platforms and packages.
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[3]B. T. Smith, D. Feng, H. Lei, D. Zheng, J. Fong, and M. Asghari, “Fundamentals of Silicon Photonic Devices ( b ),” pp.
2–8, 2006
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17.  Silicon Photonics for Exascale Systems[4]
• CMOS-compatible fabrication and compact integration within
the computing/memory chips.
• These photonic devices are implemented on a silicon on
insulator (SOI) which can be integrated with a computing chip
in the CMOS layer, on top of the metal stack.
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[4] D. Nikolova, R. Hendry, Q. Li, S. Member, D. Calhoun, and K. Bergman, “Silicon
Photonics for Exascale Systems,” vol. 33, no. 3, pp. 547–562, 2015.
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18.  Some of the photonic devices that are being used on
silicon platform-
• SiGe HBT(Heterojunction Bipolar Transistors) based
photonic devices
• Ge/GeSn hetero-phototransistors (HPT) on Si substrate
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19. SiGe HBT:
• SiGe has a smaller band gap than Si.
• Increasing Ge from emitter to collector creates a conduction
band gradient that accelerates the transport of electrons
injected from the emitter across the base.
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Fig.8 Band diagram of a graded base SiGe HBT and a
comparatively constructed Si BJT
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20.  Less potential barrier increased collector current
enhanced gain
 Silicon bipolar integrated circuits for10 Gb/s optical comm.
systems
 Research is underway on SiGe heterojunction bipolar circuits
for 20 and 40 Gb/s systems
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improved high frequency performance
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21. Ge/GeSn hetero-phototransistors on Si substrate:[5]
 Si-based detectors cannot be used in the standard
telecommunication windows around 1.55 µm as the
cut-off wavelength of Si is 1.1 µm.
 What has led to the fabrication of the GeSn-based
photodetectors?
• The alloy Ge1-ySny has a band gap lower than that of strained
Ge .
• Larger absorption coefficient in both the C and L bands.
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[5] Basu, R., Chakraborty, V., Mukhopadhyay, B., & Basu, P. K. (2014). Predicted
performance of Ge/GeSn hetero-phototransistors on Si substrate at 1.55 μ m.
Optical and Quantum Electronics, 47(2), 387–399.
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22.  HPTs possess internal gain, but no excess noise,
which is present in APDs due to the random
avalanche multiplication process.
 HPTs has been done with InGaAs/InP or
GaAs/AlGaAs or using other III -V compound
semiconductors and SiGe alloy.
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23.  Discussed main advancements and areas of photonic devices.
 The field of Photonic devices is growing .
 Despite significant breakthroughs, there are still unexplored
areas.
 Future of photonics devices-
• E-paper for all
• Solar panels widespread
• Light emitting fabrics
• Optical memory
And Beyond…...........
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24. [1] F. Bonaccorso, Z. Sun, T. Hasan, and a. C. Ferrari, “Graphene Photonics
and Optoelectronics,” vol. 622, no. August 2010, pp. 1–26, 2010.
[2] A K Sharma, R. Jha, and B. Gupta, “Fiber-Optic Sensors Based on
Surface Plasmon Resonance: A Comprehensive Review,” Sensors
Journal, IEEE, vol. 7, no. 8, pp. 1118–1129, 2007.
[3] B. T. Smith, D. Feng, H. Lei, D. Zheng, J. Fong, and M. Asghari,
“Fundamentals of Silicon Photonic Devices ( b ),” pp. 2–8, 2006
[4] D. Nikolova, R. Hendry, Q. Li, S. Member, D. Calhoun, and K. Bergman,
“Silicon Photonics for Exascale Systems,” vol. 33, no. 3, pp. 547–562,
2015.
[5] Basu, R., Chakraborty, V., Mukhopadhyay, B., & Basu, P. K. (2014).
Predicted performance of Ge/GeSn hetero-phototransistors on Si
substrate at 1.55 μ m. Optical and Quantum Electronics, 47(2), 387–399.
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25. THANK YOU
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