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Cours - 8B-253-PHO : Optoelectronics

Domaine > Photonique.


This course is devoted to the principle and related techniques to modulate, transport and detect analog or digital information carried by an optical wave. First, the basic principles of operation of optical fiber communication systems are provided, covering modulation formats, optical amplifier and optical receiver performances. The second part of the course focus on the optical modulation techniques based on electrooptic and acoustooptic effects. Electrooptic (EO) effect is studied in detail, followed by an analysis on the performances of polarization, amplitude and phase EO based modulators. A dedicated chapter is devoted to EO effect in liquid crystals that are applied in commonly used spatial light modulators. Lastly, acoustooptic effects that deal with the interaction between an optical wave and a monochromatic acoustic wave will be described, and illustrated through various functionalities like: amplitude light modulators, beam deflectors, frequency shifters, tunable filters, spectrum analyzers…

Objectifs pédagogiques

By the end of the course, students will be able to:

  • Describe the principle and related techniques used to modulate in the spatial, temporal, frequency or polarization domains an optical wave through acoustooptic and electrooptic effects.
  • Compare the performances and the limits of those techniques
  • Model, calculate the performances achieved with modulator devices in various configurations described in the course
  • Understand the techniques and principles used for the transmission and detection of optical signals at rates of several hundred Gbit/s
  • Evaluate the performance in terms of signal-to-noise ratio of a digital data transmission system operating in linear regime with a direct, self-heterodyne or coherent detection scheme.
  • Carry out an initial dimensioning of an optical transmission system operating in the linear regime (in free space or by optical fibre)

Diplôme(s) concerné(s)

UE de rattachement

Format des notes

Numérique sur 20

Pour les étudiants du diplôme Diplôme d'ingénieur de l'Institut d'Optique Théorique et Appliquée

Le rattrapage est autorisé (Note de rattrapage conservée écrêtée à une note seuil de 12)
  • le rattrapage est obligatoire si :
    Note initiale < 6

Le coefficient de l'UE est : 30

Programme détaillé

Section 1 : Introduction to optical communication

  1. Modulation formats and techniques

    Electro-optic modulator

    Amplitude and phase modulation

    Optical spectra 

  1. Optical receiver performances

    Noise detection

    DIRECT and COHERENT detection : principle

    Bite Error Rates and Quality Factor

    DIRECT and COHERENT detection : Signal to Noise Ratio (SNR)

  1. Optical amplification

    Erbium doped fiber amplifier : principle of operation

    Noise Figure

    Amplified transmission : noise accumulation 

  1. Pre-amplified optical receiver

    Optical Signal to Noise Ratio : SNRoptique

    SNR for DIRECT and COHERENT detection with pre-amplification

 Section 2 : Electrooptic modulation


Short reminder about properties of birefringent materials

Modification of the index ellipsoid under EO effects

Modification of the impermeability tensor coefficients by linear EO effect

Example : linear EO effect in KDP


Polarization modulators

Amplitude modulators

Phase modulators


Longitudinal modulators

Transverse modulators

Integrated-optical modulators  

Section 3 : Acoustooptic modulation

1 - Introduction to acoustooptic interaction

2 - Photoelastic effect

    Mechanical strain tensor

    Strain-optic tensor

3 - Bragg diffraction by an acoustooptic grating

    Permittivity variation under elasto-optic effect

    Acoustooptic Bragg diffraction

4 - Acoustooptic modulators

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