Nanoscale Cr 4

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Nanoscale Cr 4 Doped Olivine Crystallites in
Glass-Ceramics for NIR Optical Amplifiers and
Lasers

• By Fayette Colon
• Mentor Mikhail Sharonov
• Assistant Mentor Thandar Myint

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Abstract

• The purpose of this experiment is to fabricate
• Cr 4 ion doped laser crystals and
  characterize glass ceramics containing nanoscale
  crystallites of Cr 4 - doped laser materials
  such as Cr 4 Mg2SiO4 and Cr 4 Ca2GeO4. The
  glass ceramic is important because it can be used
  in several applications such as the fiber
  amplifier, fiber laser and for other medical
  purposes.

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Objectives

• Material preparation
• To uncover a proper host for the Cr 4 ion
  through the research of the LiInSiO4 and CaSiO4
  systems.
• Optical characterization of materials
• To compare a glass ceramic doped with
  nanocrystallite Cr4 ions and bulk laser
  crystals,
• such as Cr 4 Mg2SiO4 or Cr4 Ca2GeO4 to
  observe whether it has the same characteristics
  as the individual bulk crystals.

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What is a laser?

• It is an acronym for Light Amplification by the
  Stimulated Emission of Radiation
• A laser produces near- monochromatic light
• Has a single precise wavelength or hue
• The light is coherent
• The photons emitted have a definite phase
  relationship
• Laser beams are collimated
• They are narrow and concentrated

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Electronics to Support Synchronization Between
the Lasers
The circuit used two non-inverting operational
amplifiers In a non-inverting input the output
polarity is the same as the input polarity
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Laser System
Thandar Myint
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Importance of the Circuit

• The circuit serves as a component to the laser
  system
• It is designed to aid in synchronizing the pump
  and the signal pulses in order to reach the laser
  amplifier at the same time.

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Raman Measurement
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Spectrometer/ Detector

• A Spectrometer is an optical instrument which
  measures the properties of light over a portion
  of the electromagnetic spectrum. The measured
  variable is often the intensity and the
  independent variable is the wavelength.

• A Detector is a device which is designed to
  detect the presence of something as well as to
  emit a signal in response.

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Experimental Set Up
F. Colon
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Experimental Information

• A HeNe laser was used it generates a 632.3nm
  laser line and its power is about 1mW.
• The light passed through a filter (which
  selectively transmits certain portion of light)
  then reflected onto a mirror at 45 degrees
• The light beam then reflected onto a second
  mirror and through a second filter
• The laser was again reflected onto a mirror
  through a lens (which is 12cm from the crystal)
  to be reflected on a fourth mirror and into the
  glass ceramic crystal
• The light then scattered and was collected by a
  Camera Lens following which it went into the
  Spectrometer.
• The Camera Lens must be finely adjusted to
  receive good focusing

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Results
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Further Results
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Analysis of the Results

• The graph shows the light intensity versus
  wavelength of HeNe laser.
• The maximum power of the HeNe laser is located at
  632.8nm.
• The shape of the image is well-known Gaussian
  shape, which means that the intensity is
  concentrated in the center and gradually
  decreases at the tails.
• Although this was merely a test trial for the
  experiment its importance lies with the layout of
  the experimental instruments.

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Further Work

• The Research team will use the results of the
  test trial to create a more efficient layout for
  the experiment.
• Following which the high intensity laser will be
  used for the actual experiment along with the
  circuit created
• Completion of this experiment is important
  because the data received will show the
  characteristics of the glass ceramic obtaining
  this knowledge will lead to realize the proposed
  application such as optical amplifiers.

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Acknowledgements

• Mentors Mikhail Sharnovo and Thandar Myint
• NASA SHARP
• NASA COSI and DoD NPC Summer Program
• City College of New York
• CREST CMMS
• NYC-MTA

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References

• Characteristics of Laser Light
• http//en.wikipedia.org
• What is a Laser?
• http//en.wikipedia.org
• Detector
• http//en.wikipedia.org