PHOTONICS

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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