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Quantum Lasers
EE 566 Optical Communications
Massoud MOMENIGrad Microelectronics
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Overview
1. Quantum Lasers Q L
a) Single-Quantum Well Laser SQW L
b) Multiple-Quantum Well Laser MQW L
c) Separate Confinement Heterostructure Laser SCH L
d) Graded-Index SCH Laser GRINSCH L
e) Quantum Cascade Laser QC L
f) Quantum Dot Laser QD L
2. Summary
3. References and…
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1. Quantum Lasers
LASER = Light Amplification by Stimulated Emission of Radiation
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Single-Quantum Well Laser (SQWL)
Double Heterostructure:
GFpFn EEE )(1)( VVVC EfhfEf or, alternatively,
Basic Laser condition:
nm
hf
V > 0
P p N
EV
EC
EFpEFn
Eel
Ehole
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Refractive Index and Mode Profile
p+ n+ P p n+ P p N
Homostructure Single Heterostructure (SHS) Double Heterostructure (DHS)
n
optical field
Optical confinement is higher for a DHS
Electrical confinement is higher for a DHS lower Ith
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Multiple-Quantum Well Laser (MQWL)
P p P
EV
EC
MQW using isotype SQW:
mini bands
P p P p P p P p P
hf hf hf hf
MQW DFB
MQW DFB
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Separate Confinement Heterostructure (SCH)
hf
EV
x
P p N
EC
InP
InGaAsP InGaAsP
InP
InG
aAsP
InG
aAs
MQW regionSCH region SCH regioncladding cladding
5 nm 10 nm 50 nm
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EC
EG ( InP )
Graded-Index SCH Laser (GRINSCH L)
EG ( InGaAsP )EG ( InGaAs )
EV
GRIN regionGRIN region MQW region
n
cladding cladding
x
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Quantum Cascade Laser (QC L) — Principle
interband transition:
intersubband transition:
Eappl
Tunneling rate >> 3 = 1 psand 2 = 0.3 ps << 32 > 1 ps population inversion
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QC Laser — Data
Data [1–5]:
Applications [1–6]:
• Military and Security
• Commercial, Medical
• Free-Space Optical Communication Systems and Astronomy
• Gas detection based on laser spectroscopy with CW or pulsed QC DFB lasers (chemical sensors)
L[m]
Pout[mW]
Jth [A/cm2] /
Eth [kV/cm]
operation mode
T first demo
[year]
$$$
3.4 – 80 200 – 300 (CW) up to 1000 (PM)
250 – 290 /7.5 – 48
PM or CW on cooler
350 1994 AT&T Bell Labs
(later)
Material systems: GaAs based, InP based, Si / SiGe on GaSb, InAs / AlSb on GaSb
CW = continuous wave; PM = pulse mode
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Quantum Dot Lasers (QD L) — 1. Principle
b) tunneling-injection QD laser:a) schematic view:
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QD L — 2. Principle
a) Prevention of parasitic b) “Limit case” recombination in the OCL
n-cl
addi
ng
p-cl
addi
ng
OC
L
OC
L
QD
electrons
holes
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2. SummaryQuantum Lasers use the structures we have discussed so far in order to
1. optimize the properties of a simple Fabry-Perot Laser (L, R, g, ),
2. Increase efficiency ()
3. reduce the threshold current (Ith) and its temperature dependency,
4. change the wavelength of the laser beam (),
5. achieve continuous wave (CW) operation @ RT, and
6. increase the output power (P).
Fabrication:
1. Metallorganic chemical vapor deposition MOCVD2. Molecular beam epitaxy MBE
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What we left out… (more presentations?)Basics:
o Quantum Effects (energy quantization, first and second order tunneling effect,…)
o Simple Fabry Perot Laser (FPL) and characteristics
o Concept of gain-guided (active) or index-guided (passive) lasers (wave guiding), e.g. in buried heterostructure lasers (BHS), or separate lateral confinement (LC)
o Distributed bragg reflector (DBR), distributed feedback bragg (reflector) (DFB)
R&D:
Blue Lasers or GaN Lasers
Tunable Lasers (TL) or Tunable Diode Lasers (TDL)
Vertical Cavity Surface Emitting Lasers (VCSEL)
Strained heterostructure QW lasers
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3. References (QC L)
[1] Sirtori C., Nagle J., “Quantum Cascade Lasers: the quantum technology for semiconductor lasers in the mid-far-infrared.” Comptes Rendus Physique, In Press, Corrected Proof, Sep. 2003http://www.sciencedirect.com/science/article/B6X19-49FGMWM-6/2/299ee308e587b6215f4731fbe5cfd566
[2] Garciaa M., Normand E., Stanley C.R., Ironside C.N., Farmer C.D., Duxbury G., Langford N., "An AlGaAs–GaAs quantum cascade laser operating with a thermoelectric cooler for spectroscopy of NH3.“ Optics Communications, In Press, Uncorrected Proof, Sep. 2003.http://www.sciencedirect.com/science/article/B6TVF-49FXMFB-3/2/607fb52178f815aca3c266c7cf670524
[3] Köhler, R., Tredicucci A., Beltram F., Beere H.E., Linfield E.H., Davies A.G., Ritchie D.A., Iotti, R.C., Rossi F., "Terahertz semiconductor-heterostructure laser" letters to nature, vol. 417 no. 6885, pp. 156–159, May 2002.
[4] Sirtori C., "Applied physics: Bridge for the terahertz gap." Nature news and views, vol. 417, no. 6885, pp. 132–133, May 2002.
[5] Beck M., Hofstetter D., Aellen T., Faist J., Oesterle U., Ilegems M., Gini E., Melchior H., “Continuous wave operation of a mid-infrared semiconductor laser at room temperature.” Science, vol. 295, issue 5553, pp. 301–305, Jan. 2002.
[6] Kosterev A.A., Tittel F.K., "Chemical Sensors Based on Quantum Cascade Lasers." IEEE Journal of Quantum Electronics, vol. 38, no. 6, , pp. 582–591, June 2002.
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4. References (QD L)
[7] Asryan L.V., Luryi S., "Tunneling-Injection Quantum-Dot Laser: Ultrahigh Temperature Stability" IEEE Journal of Quantum Electronics, vol. 37, no. 7, pp. 905–910, July 2001.http://www.ee.sunysb.edu/~serge/177.pdf http://www.ee.sunysb.edu/~serge/publist.pdf
[8] Asryan L.V., Luryi S., Suris R.A., "Internal Efficiency of Semiconductor Lasers With a Quantum-Confined Active Region." IEEE Journal of Quantum Electronics, vol. 39, no. 3, pp. 404–418, March 2003.http://www.ee.sunysb.edu/~serge/191.pdf
[9] Pelton M., Yamamoto Y., "Ultralow threshold laser using a single quantum dot and a microsphere cavity." Physical Review A, vol. 59, no. 3, pp. 2218–2241, March 1999.
[10] Maximov M.V., Asryan L.V., Shernyakov Yu.M., Tsatsul’nikov A.F., Kaiander I.N., Nikolaev V.V., Kovsh A.R., Mikhrin S.S., Ustinov V.M., Zhukov A.E., Alferov Zh.I., Ledenstov N.N., Bimberg D., "Gain and Threshold Characteristics of Long Wavelength Lasers Based on InAs/GaAs Quantum Dots Formed by Activated Alloy Phase Separation." IEEE Journal of Quantum Electronics, vol. 37, no. 5, pp. 676–683, May 2001.
[11] Luryi S., Xu J.M., Zaslavsky A., Future Trends in Microelectronics: the Nano Millennium, Wiley-IEEE Press, 2002, pp. 219–230.http://www.ee.sunysb.edu/~serge/180.pdf
[12] Bludau, W. Halbleiter-Optoelektronik, München, Wien: Hanser, 1995, pp. 122–123, 151–155, 180–187.
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History of Lasers
Welch D.F., “A Brief History of High-Power Semiconductor Lasers.” IEEE Journal of Selected Topics in Quantum Electronics, vol. 6, no. 6, pp. 1470–1477, Dec. 2000.
Laser history 1917–1996:http://home.achilles.net/~jtalbot/history/
Laser at Bell Laboratories from 1958–1998:http://www.bell-labs.com/history/laser/
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Where to find papers…
Where to look for articles on these topics: (use ScienceDirect & IEEE Xplore®)
IEEE http://www.ieee.org/IEEE Journal of Quantum ElectronicsIEEE Photonics Technology LettersIEEE Transactions on Electron DevicesIEEE Proceedings on Optoelectronics
Nature http://www.nature.com/
Science http://www.sciencemag.org/
Applied Physics Letters http://ojps.aip.org/aplo/top.jsp
Laser Focus World http://lfw.pennnet.com/home.cfm
Elsevier http://www.elsevier.com/locate/optcomElsevier Optics CommunicationsElsevier Comptes Rendus Physique
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Wanna BUY a quantum laser?
Go online
Click on http://lfw.pennnet.com/home.cfm to get to Laser Focus World
Look for “Buyers Guide” in the left column and click on it!
Type the keywords! E.g. “Quantum Cascade Laser”
You’ll get a list with companies (in this case just one) offering a quantum laser or something related to it, click on the entry and then the company’s link!
You are transferred to the company’s website
BUY ALL YOU WANT OR ALL YOU NEED!(datasheet, images etc. readily available)
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1. Example: Quantum Cascade Laser
Laser Components Instrument GroupAddress: 10 Upton Drive
Wilmington, MA 01887Phone: 978-658-9100Fax: 978-658-1888URL: www.laser-components.comEmail: [email protected]: 5Year Founded: 1976Job Openings: unfortunately no…
For prices, talk to Gary Hayes:
This product is a…
HIGHLIGHT!
10.000 – 15.000 US $
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n
NE
2. Example: Single-Mode SQW GRINSCH L
Axcel Photonics, Inc.Address: 45 Bartlett Street
Marlborough, MA 01752Phone: 508-481-9200Fax: 508-481-9261URL: http://www.axcelphotonics.com/Email: [email protected]: 18Job Opening: Office Manager
For prices, call John Carry:
1 US $ per mW, up to 500 mW
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Pricelist (all in US Dollars)
• MQW DFB Structures:InGaAsP MQW DFB Structure @ 1550 nm 779.35InGaAsP MQW DFB Structure @ 1310 nm 467.00
(more than 600 $ off if you choose a FP!)AlGalnP Index guided MQW structures 24.00 – 189.70
• VCSEL Structures: 8.00 (for each of 50) – 26.00 (for a single one)
• Blue Laser Module 1,795.00 – 2,695.00System 2,195.00 – 9,495.00
• Quantum Cascade Lasers astronomical, even for the diode only
Sources: INTELITE, Inc. http://www.intelite.comThorlabs GmbH http://www.thorlabs.com/index.cfmLaser Components Instrument Group www.laser-components.comAxcel Photonics, Inc. http://www.axcelphotonics.com/
VCSEL
MQW DFB
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Abbreviations (Alphabetical Order)
BHS / BH Buried Heterostructure
CW Continuous Wave QL Quantum Laser
DBR Distributed Bragg Reflector QW Quantum Well
DFB Distributed Feedback Bragg SCH Separate Confinement Heterostructure
DHS Double Heterostructure SQW Single-Quantum Well
FP Fabry Perot QC Quantum Cascade
GRINSCH Graded-Index SCH QD Quantum Dot
LASER Light Amplification by Stimulated Emission of Radiation
SHS Single Heterostructure
LC Lateral Confinement SLC Separate Lateral Confinement
MQW Multiple-Quantum Well TL Tunable Lasers
OLC Optical Confinement Layer TDL Tunable Diode Lasers
PM Pulse Mode VCSEL Vertical Cavity Surface Emitting Lasers
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For those who want to know more…
Tutorial on Semiconductor Lasers