NASA Technical Reports Server (NTRS) 20020043407: Far-Infrared Generation in Sb-Based Quantum Wells Pumped by Near-Infrared Diode Lasers

3 Pages·0.07 MB·English

by  NASA Technical Reports Server (NTRS)

Introduction: Whys
Applications of THz Wave
• Why Intersubband?
• Teraherlz modulatioh and switching
• Long wavelength generation
• Chemical, biochemical, and astrobiological detection
, Diminished Auger process_
and sensing
• Large transition matrix elements
• Materials and security Inspection
Why
• High bandwidth, energy efficient, secure data link • Sb-QWS?(unique bandedge lineups)
• .... many more applications • Flexibility inwavelenglh design
• Deep conduction band wells allowing NIR (diode)
laser pumping
Introduction: Whys
4,
lntroduction:
PresentApproach
• CO=_ pumpedGaAa/AIGaAI QWs emitting15.5mm (Pedl-
• Why optical pumping?
Sud)
• Less reliant on population inversion
• Utilization of resonant nonlinearities
• Lower carrier concentration and lower free carrier
absorption
• Absence of heavily doped layers for contacts and • FIR Generation byDouble-Resonant DFG (Lucent)
injectors
• Potential integration ifdiode lasers used as pumping
2
Proposed Solution:
D_eLa__umpeqdW-U_nd e_seTdHzSoun:es Raman Enhanced Optical Gain
DcD_PGt_e_._hs_omnem i 3OO
ll3 _ T=77 K
r--I i_1 r"
200
t_lonon P_u,'r-_ 1.0 MWlcn_
=mira,, .m*oq noQ=*
loo
• a , ,
010 15 20 28 30 36 40
Photon Energy (meV)
Diode-LaserPumpedDifferenceFrequency
Generation (InGaAs/InP/AIAsSbQWs)
THz Laser Gain inInGaAs/InP/AiAsSb Quantum Wells
| I I m II
=-m=_ "'_,' i
,_ t_;l_At=1'_0¢=' II I II
|-
r'I-' '
m I
0
Io I l 4 k I LI
0 LO _ _ m O_ I_(m
l$ 20 _ J _ 40
_trM_v)
3
[nAs/GaSb/AlSb Quantum Wells InAs/AlSb Double QWS: DFG Scheme
_'_,,,n--nq,c-
,_UU'
..... -[__ILl
lllInAs/AlSb Triple QWs: Laser Scheme
•l Qr _l _, 11 11 _r 1| m, za zs
4