Compact Diode Laser for Near Infrared Methane Spectroscopy - - PowerPoint PPT Presentation

Compact Diode Laser for Near Infrared Methane Spectroscopy

Ottillia Ni Me nto r: Dr. K rista n Co rwin Aug ust 5, 2016

Motivation

• E

xpa nd g a s-fille d ho llo w fib e r re fe re nc e s to 1.6 mic ro ns wa ve le ng ths.

• Ab so rptio n spe c tro sc o py a nd sub -Do pple r spe c tro sc o py in

me tha ne -fille d ho llo w fib e rs

Challenges of the Diode Laser

• Using the L

ittro w c o nfig ura tio n to c a lc ula te the diffra c tio n a ng le o ff the diffra c tio n g ra ting .

• Re c o nstruc ting a nd ma c hining o f a n a da pte d dio de la se r

de sig n a t the ne w g ra ting a ng le .

• Re de sig ning the mirro r mo unt to a vo id b e a m c lipping , pa ssing

a b e a m ra dius 4x the full width ha lf ma ximum (F WHM).

• Ne e ding hig h po we r to sa tura te me tha ne fo r sub -Do pple r

spe c tro sc o py

Methane (CH4)

ν3= 3158.6 c m -1, 2ν3= 6317.2 c m -1

4.0Å

https:/ / www.re se a rc hg a te .ne t/ fig ure / 278652214_fig 4_F ig ure -18-18-Me tha ne -vib ra tio na l-no rma l-mo d e s http :/ / www.nist.g o v/ pml/ e le c tro ma g ne tic s/ g rp05/ o the r-a c tivitie s.c fm

Assembling a Compact Diode Laser

Interior of the Diode Laser

L ittro w Co nfig ura tio n

https:/ / e n.wikipe d ia .o rg / wiki/ Bla ze d _g ra ting

d= line spa c ing

α= inc ide nc e a ng le β= diffra c tio n a ng le ΘB= b la ze d a ng le

Laser Parts

• T

he rmo e le c tric c o o le rs (T E Cs) - he a t pumps use d to c o o l syste ms.

• PZT

– fine tune po sitio n o f the the la se r

• T

he rmisto r- e le c tric a l re sisto r use d fo r me a sure me nt a nd he a t c o ntro l

• T

e mpe ra ture Chip – de te rmine s the te mpe ra ture o f la se r

http://www.ebay.com/itm/400W-12V-Thermoelectric-Cooler-Peltier-Plate-TEC-NEW-/111201613218

Powering the diode laser

Cable: 6ft long

Future Works

• Alig n a nd fib e r-c o uple the la se r, fill a ho llo w c o re fib e r with

me tha ne , a nd tune the la se r to the re so na nc e o f the me tha ne line

• Co nduc t a b so rptio n spe c tro sc o py a nd sub -Do pple r

spe c tro sc o py a t 1.6 mic ro ns

• De ve lo p se a le d ho llo w-c o re fib e rs

fille d with me tha ne a b so rb ing la se r lig ht a s a fre q ue nc y re fe re nc e .

https://www.thorlabs.com/thorproduct.cfm?partnumber=HC19-1550

Ø20 µm

Acknowledgements

Spe c ia l tha nks to :

• Dr. K

rista n Co rwin

• Dr. Bre tt De Pa o la
• Dr. Bria n Wa shb urn
• Rya n L

ude r

• Sa je d Ho sse ini-Za va re h, Ne da Da da shza de h, K

usha a n We e ra sing he , Ma na sa T hirug na na sa mb a nda m

• F

e llo w Physic s RE U Pe e rs

• Dr. Bre tt F

la nde rs

• K

im Co y T his wo rk is pa rtia lly funde d b y the Na tio na l Sc ie nc e F

• unda tio n

(NSF ) a nd the Air F

• rc e Offic e o f Sc ie ntific Re se a rc h (AF

OSR) thro ug h NSF g ra nt numb e r PHYS-1461251.

Questions?