Irsens2

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IRSENS II A Multi-Gas Sensor for Air Pollutants and Greenhouse Gases S.Nida1, M.J.Süess1, J.M.Wolf1, M.Beck1, J.Faist1 L. Emmenegger2, B. Tuzcon2, R. Brönnimann2, H. Looser3, T. Südmeyer4 ETH Zurich1 EMPA Dübendorf2 Fachhochschule Nordwestschweiz3 Université Neuchâtel4

IrSens 2 – Selam Nida

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Click to edit Master text styles Motivation

Gases Medical diagnosis

Environment

Sensing of small molecules (CO, CO2, NxOy, ...)

Air quality control

Selective Sensitive

Portable Low power

Infrared Spectroscopy

Semiconductor System

Process control

Leak detection

Traffic security IrSens 2 – Selam Nida

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Click Goal to edit Master text styles

Current air pollution monitor (NABEL Station) in EMPA, Dubendorf

State of the Art method • Bulky • Expensive • High power consumption

Detect the 10 most important atmospheric gases with Infrared Laser Spectroscopy IrSens 2 – Selam Nida

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Click to edit Methods of Laser Master Spectroscopy text styles Covalently bonded molecules => mechanical oscillators Rotational Vibrational modes of molecules

Ro-vibrational energy level diagram

Allowed transitions at various resonant frequencies

Absorption at this resonant frequencies • Unique fingerprint

sensitive to mass (ω=√k/m)=> distinguish Isotopes IrSens 2 – Selam Nida

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Click toAbsorption Optical edit Master Spectroscopy text styles – MIR Region MIR Energy Not enough energy to excite vibration of Molecular bonds

Fundamental mode

Overtones

Ionization

Fundamental absorption fingerprint of 10 most important pollutants IrSens 2 – Selam Nida

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Optical Click toSpectroscopy edit Master text styles

L = 36 m, p = 100 hPa 1 ppm NO2 1.3% H2O

Transmission (%) Transmission (%)

100 100 9595 9090 8585 8080

Laser tuning

1598 1598

1599 1599

1600 1600

1601 1601

1602 1602

-1

Wavenumber (cm ) -1) Wavenumber (cm

1. Tuning of the laser emission across the fingerprint region 2. Measure how much light is absorbed by the sample

IrSens 2 – Selam Nida

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Click to Spectroscopy Optical edit Master text – Quantum styles Cascade Laser Barrier

well

Barrier

Inter-subband Lasers Multiple quantum wells

Quantum Cascade Laser Delta like joint density of states

Broad Gain: transitions possible over a broad spectral range

Selectivity

Tunability IrSens 2 – Selam Nida

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Click to editCell Interaction Master text styles Requirement: •Large optical path length- to increase the absorption signal •Minimize fringes –reduce the noise Parabolic multi-pass reflection cell •Confocal/parabolic =>12m/300ml •Robust absorption mask –highly reduced interference fringes –reduce the noise

Parabolic Multi-pass reflection cell M.Mangold, B.Tuzcon et al, Switzerland Patent 01884/12, 2012.

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Click to edit Master Achievements so fartext styles CO2 Spectroscopy 17O12C16O 18O12C16O 13C16O

12C16O

2

2

CO2 isotope analyzer Helicobacter pyroli Infection marker Quantify soil exchange Tracer for stratospheric air

Jouy et al, Analyst 2015 IrSens 2 – Selam Nida

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Click to edit Master Achievements so fartext styles Cocaine Spectroscopy

Jouy et al, Analyst 2015

Measurement of Cocaine in PCE

NO2 Spectroscopy the SPIE award for miniaturized Platforms at the Photonics Europe Innovation Village Dr. Markus Mangold Postdoctoral fellow c/o Dr. Lukas Emmenegger Laboratory for Air Pollution EMPA DĂźbendorf

A 36x40 cm spectroscopic platform IrSens 2 – Selam Nida

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Click to Goal Current edit Master -Multiple textGas styles sensing Simultaneous detection of the 10 most important gases

Detector

Laser Requirement: Distinct emission wavelength (Laser) for each gas Challenge: Power loss and beam combining complexity added

However, most of the components can be shared

IrSens 2 – Selam Nida

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Click to Goal Current edit Master -Multiple textGas styles sensing Simultaneous detection of the 10 most important gases

Detector

Laser Solution: One laser emitting at multiple wavelengths

Sharing the rest of the components

IrSens 2 – Selam Nida

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Click to edit Master text styles Multi-Wavelength Operation Cladding

in QCLs

Fabry Perot Cavity

5.38 10

5.32

Wavelength(m) 5.26 5.21

5.15 10

Intensity (AU)

1.5mmx7um

Active region (AR)

8

8

6

6

4

4

2

2

0 1860

0 1880

1900

1920

1940

Wavenumber (cm-1) EV2021-3FPDFBL

IrSens 2 – Selam Nida

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Click to edit Master text styles Multi-Wavelength Operation

in QCLs

Wavelength Selection- Distributed Feedback Lasers (DFBs) Cladding

DFB

AR

Active region (AR)

Periodic Modulation of the waveguide effective index

λ=2*Λg*neff H. Kogelnik and C. V. Shank, Journal of Applied Physics 43 (1972).

A. Yariv and P. Yeh, Optical Waves in Crystals (John Wiley and Sons, 1984).

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Click to edit Master text styles Multi-wavelength operation

of QCLs

Distributed feedbacks (DFB)

T<175K

First demonstration of multi-wavelength QCLs •Two stack active region •Two DFBs Intersubband=>delta like joint density of states Straub et. al, Electronics Letters, 2002

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Click to edit Master text styles Multi-wavelength DFB

QCLs

Single mode and multi wavelength operation 1610 0.6

1615

1905

1910

1915 0.6

DFB 1 Intensity (AU)

NO2 InP cladding Active region InP:Fe insulator

NO

0.4

0.2

0.4

0.2

electrical separation 0.0 1610

1615

1905

1910

0.0 1915

wavenumber (cm-1)

Emission at two wavelengths, one at a time with electronic switch.

IrSens 2 â&#x20AC;&#x201C; Selam Nida

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Click to edit Master text demonstration styles Twin-DFB QCLs Multiple gas (NO/NO2) detection from Automotive emission

Emissions in ambient air measured by a dual-QCL, comparison with chemo luminescence data (CLD).

J. Jagerska et al. APL 105, 161109 (2014).

J. Jagerska et al., Optics Express 23, 1512 (2014).

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Click to edit Master Packing moretext styles Triple Wavelength Operation Triple stack active region Triple section DFB

DFB 1 electrical separation

electrical separation

Problem: Reduced power from the back section Solution: Sampled Grating DFBs Proof of concept demonstrated (J Wolf, A Bismuto Unpublished)

IrSens 2 â&#x20AC;&#x201C; Selam Nida

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Click to edit Master text styles Plans conc. range [ppb]

waven umber

2-20

1046.4

1700

1275.5

SO2

0.1-10

1352

NO2

1-100

1600

NO CO ,N2O ,H2O

1-100

1900

1-10

2179

380

2281

Trace gas NH3,O3 CH4 ,N2O ,H2O

CO2

Triple Color QCL DFB 1

Twin color DFB

Detecting 10 gases with 3 lasers IrSens 2 â&#x20AC;&#x201C; Selam Nida

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Click to edit Master text styles

T. Südmeyer

S. Nida M. Suess P. Jouy J. Faist

L. Emmenegger B. Tuzcon M Mangold J Jagerska R. Brönnimann

Thank you IrSens 2 – Selam Nida

H. Looser

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