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Welcome to

Phys 774: Principles of Spectroscopy

Fall 2007

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Instructor:Andrei SirenkoAssociate Professor at the Dept. of Physics, NJIT

http://web.njit.edu/~sirenko

476 Tiernan

Office hours: After the classes on We.’s or by appointment973-596-5342

Class Schedule:Wednesday 11:30am - 12:55pm | FMH 106Friday 1:00pm - 2:25pm | FMH 203

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How EM waves are produced ?

How can we analyze EM waves ?

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Spectrum of Electromagnetic Radiation and Light

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The most important information arises when the wavelength of the radiation is similar to, or smaller than, the size of the spacing between the objects being studied.

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Spectroscopy…

Source of Radiation or Excitation

Sample

Spectrometer + Detector

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Classification of Spectroscopy…

Source of Radiation or Excitation

Sample

Spectrometer + Detector

… by frequency range:•X-ray•UV•Infraredetc

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Classification of Spectroscopy…

Source of Radiation or Excitation

Sample

Spectrometer + Detector

… by the type of the radiation source:• Broadband (synchrotron radiation)• Laser• CW / time-resolved

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… by the type of Excitation:

Chemoluminescence Bioluminescence

Electroluminescence (E-field, injection)Cathodoluminescence (electron beam)

MechanoluminescenceTriboluminescenceFractoluminescencePiezoluminescence

Photoluminescence (light)Phosphorescence Fluorescence

RadioluminescenceSonoluminescence (sound)

Thermoluminescence (heat)

Sample

Spectrometer + Detector

Classification of Spectroscopy…

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Example: Photoluminescence Spectroscopy

Source of Radiation or Excitation

SampleGaAs, InP, …

Spectrometer + Detector

Photoluminescence in SEMICONDUCTORS and

SEMICONDUCTOR DEVICE STRUCTURES

Goal: Bandgap Measurements (details of the electronic

structure)

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Sample

Spectrometer + Detector

… by the type of detection:•Fourier transform Spectroscopy•Spectrographic Spectroscopy•Ellipsometry (polarization)•Moessbauer Spectroscopy (v)•Electron Energy Loss Spectroscopy (V)

Classification of Spectroscopy…

Source of Radiation or Excitation

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Spectroscopy

Sample

Spectrometer + Detector

Processes in the SAMPLES• Raman Scattering Spectroscopy• Transmission / Reflection /Absorption• Nonlinear Spectroscopy• Time-resolved Spectroscopy• Modulation Spectroscopy

Source of Radiation or Excitation

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Resolution depends on d – number of groves per mm

How can we analyze EM waves ?

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Wavelength Position conversionBuilding a Grating Spectrometer / Spectrograph

y

CCDCharge-coupled device

Broad-band light

D

Slit (exit)

Slit (entr.)

6 cos10 [ / ]d nm mmdy m d Dλ β=

⋅ ⋅

d [grove/mm]m - order

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Czerny-Turner Configuration

Grating Spectrometer / Spectrograph /Monochromator

CCDPMT orPhotodiode

http://www.jobinyvon.com/SiteResources/Data/Templates/1divisional.asp?DocID=617&v1ID=

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Czerny-Turner Configuration

Grating Spectrometer / Spectrograph /Monochromator

PMT orPhotodiode

Sample (source of light)

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General conceptNA and f/number

PMT orPhotodiode

n nn

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Bandpass and resolution conceptNA and f/number

PMT orPhotodiode

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Bandpass = FWHM

NA and f/number

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BandpassNA and f/number

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BandpassNA and f/number

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BandpassNA and f/number

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Example

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Example

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The interaction of radiation with matter

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The interaction of radiation with matter

http://www4.nau.edu/microanalysis/Microprobe/Course%20Overview.html

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The interaction of radiation with matter

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The interaction of radiation with matter

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The interaction of radiation with matter

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The interaction of radiation with matter