Single mode: a single path of light

Cores are doped with rare earth ions such as erbium or ytterbium [3]

Normal Population Inverted Population

Source: Laserfocusworld.com

Source: Ciscohite.wordpress.com

Source: orc.soton.ac.uk

Source: alphys.physics.ox.ac.ukk

Fiberoptic101.blogspot.com

Introduction

Objective: Build a fiber laser

With   the   advent   of   a   technologically   advanced   age  rose   the   fiber   op6c   world.   Fiber   op6cs   and   lasers  have   found   applica6ons   in   photonics,   where   lasers  have  recently  been  applied  in  photothermal  imaging.  These   imaging  systems  are  being  op6mized  through  the   use   of   fiber   lasers   as   opposed   to   conven6onal  lasers.  Fibers   lasers  are  preferable  due   to   their  high  efficiency  and  compact  design.                          Generally   the   gain   fiber   is   spliced   using   specific  cleavers  and  then  fused  to  other  aspects  of  the  fiber  op6c   setup   to   create   oscilla6on   from   construc6ve  interference   in  a   resonance  cavity.   I   learned  how  to  strip,   cleave,   and   splice   these  fibers,   and   to  how   to  plot  and  analyze  data.  I  became  familiar  with  Matlab,  eventually   wri6ng   a   program   that   ploCed   and  analyzed  the   laser’s  op6cal   spectrum,  characterizing  the  laser’s  central  wavelength  and  bandwidth.  I  then  used   wavelength   division-­‐mul6plexing   to   build   a  laser.   I  measured  the  output  power  and  ploCed  the  op6cal  spectrum  through  Matlab.  

Abstract

Characterization and Construction of a Fiber Optic Laser

Janani Chinnam [1,2], Hui Liu [2], Michelle Sander [2] Stoney Creek High School, 575 E. Tienken Rd., Rochester Hills, MI 48306 [1]; Department of Electrical and Computer

Engineering, The Boston University Photonics Center, 8 Saint Mary’s St., Boston, MA 02215 [2]

Methods / Materials

Results

Conclusion

References

Acknowledgments

Fiber  probe  lasers  have  many  applica6ons,  one  of  which  is  integra6on  into  photothermal  microspectroscopy  setups  for  chemical  and  

biological  samples.  [4]  

Set-up:

1

2

3

4

Strip outer cladding off fibers

Clean and cleave fibers

Splice fibers with minimal losses

Splice APC to FBG, PC to gain, and gain to FBG (Fiber Bragg Grating)

If necessary, examine fibers with microscope and clean/polish

[3] Hecht, Jeff. Understanding Lasers: An Entry-level Guide. New York: IEEE, 1994. Print. [4] M. Y. Sander, "Compact Femtosecond Lasers and Applications in Photothermal Spectroscopy," in Imaging and Applied Optics 2014, OSA Technical Digest (online) (Optical Society of America, 2014), paper LM4D.1.

Special thanks to, The Boston University Research Internship in Science and Engineering Summer Term Program The Ultrafast Optics Laboratory located in the Boston University Photonics Center Michelle Sander, Hui Liu, Atcha Totachawattana, James Bezuk, and Ahmet Akosman for their guidance.

FBG

Output Coupler

Output 1

Erbium Fiber (Gain)

Wavelength Division

Multiplexer

977 nm

SMF

Laser Cavity

Output 2

Splicing Losses APC to FBG: 0.09 dB PC to Gain: 0.09 dB

Gain to FBG: 0.28 dB

FBG Bandwidth: 0.348 nm Center Wavelength: 1560.168 nm

Current While Lasing; 200 milliamps

Advantages  of  a  fiber  laser  as  opposed  to  a  tradi6onal  laser:  

 •  Compact  •  Highly  efficient  •  Easy  to  transport  •  Adaptable  •  High  photon  conversion  efficiency  •  Easy  to  integrate  •  Light  weight  •  Flexible  •  Rugged  •  Small  •  Inexpensive  

Optical Spectrum before lasing begins

Optical Spectrum during lasing

[4]

[4]

Source: Americomtech.com

Abblg.com Thorlabs.com