Cross-phase modulation

<h2 id="applications-of-xpm">Applications of XPM</h2>
<p>Cross-phase modulation can be used as a technique for adding information to a <a href="/facts/Light/jeofpMn4">light</a> stream by modifying the <a href="/facts/Phase_(waves)/cpGtuVll">phase</a> of a <a href="/facts/Coherence_(physics)/NF1Rgdoa">coherent</a> optical beam with another beam through interactions in an appropriate <a href="/facts/Nonlinear/4aYItALC">nonlinear</a> medium.  This technique is applied to <a href="/facts/Fiber-optic_communications/dc6S0Hg5">fiber-optic communications</a>. If both beams have the same wavelength, then this type of cross-phase modulation is degenerate.<a class="footnote-ref" id="fnref:1" href="#fn:1"><sup>1</sup></a>
</p><p>XPM is among the most commonly used techniques for <a href="/facts/Quantum_nondemolition_measurement/4E3ekgtB">quantum nondemolition measurements</a>.
</p><p>Other advantageous applications of XPM include:
</p>
<ul><li>Nonlinear optical <a href="/facts/Pulse_compression/a8PE1dA1">Pulse Compression</a> of <a href="/facts/Ultrashort_pulse/V8joGdvF">ultrashort pulses</a></li>
<li><a href="/facts/Mode-locking/7p9MjBjT">Passive mode-locking</a></li>
<li><a href="/facts/Ultrafast_optics/V8joGdvF">Ultrafast</a> <a href="/facts/Optical_switch/lz6tdqV5">optical switching</a></li>
<li><a href="/facts/Demultiplexing/YE7hK8cw">Demultiplexing</a> of <a href="/facts/Multiplexing/YE7hK8cw">OTDM</a> channels</li>
<li>Wavelength conversion of <a href="/facts/Wavelength-division_multiplexing/xSkNRxfu">WDM</a> channels</li>
<li>Measurement of nonlinear optical properties of the media (non-linear index n2 (<a href="/facts/Kerr_nonlinearity/IoJN6wlW">Kerr nonlinearity</a>) and nonlinear response relaxation time)<a class="footnote-ref" id="fnref:2" href="#fn:2"><sup>2</sup></a></li></ul>
<h2 id="disadvantages-of-xpm">Disadvantages of XPM</h2>
<h3>XPM in DWDM applications</h3>
<p>In <a href="/facts/DWDM/xSkNRxfu">dense wavelength-division multiplexing (DWDM)</a> applications with <a href="/facts/Intensity_modulation/tlAzlqpM">intensity modulation</a> and direct detection (IM-DD), the effect of XPM is a two step process:
First the signal is phase modulated by the copropagating second signal. In a second step dispersion leads to a transformation of the phase modulation into a power variation. Additionally, the dispersion results in a walk-off between the channels and thereby reduces the effect of XPM.
</p>
<ul><li>XPM leads to interchannel crosstalk in WDM systems</li>
<li>It can produce amplitude and timing jitter</li></ul>
<h2 id="see-also">See also</h2>
<ul><li><a href="/facts/Self-phase_modulation/p7Dy5Vjv">Self-phase modulation</a> — SPM</li>
<li><a href="/facts/Four_wave_mixing/0sRq9zld">Four wave mixing</a> — FWM</li>
<li><a href="/facts/Raman_scattering/obhSpgrR">Stimulated Raman scattering</a> — SRS</li>
<li><a href="/facts/Cross-polarized_wave_generation/fjov4p4y">Cross-polarized wave generation</a> — XPW</li></ul>

<h2 id="external-links">External links</h2>
<ul><li><a href="https://www.rp-photonics.com/cross_phase_modulation.html">Cross-phase modulation (RP Photonics, Encyclopedia of Laser Physics and Technology)</a></li></ul>

<h2 id="references">References</h2>

<ol>
<li id="fn:1"><p>Petrov, Nikolay V.; Sergei S. Nalegaev; Andrei V. Belashov; Igor A. Shevkunov; Sergei E. Putilin; Yu-Chih Lin; Chau-Jern Cheng (2018). "Time-resolved inline digital holography for the study of noncollinear degenerate phase modulation". Optics Letters. 43 (15): 3481. Bibcode:2018OptL...43.3481P. doi:10.1364/OL.43.003481. PMID 30067690. S2CID 51893588. <a href="https://www.researchgate.net/publication/326424496" target="_blank">https://www.researchgate.net/publication/326424496</a> <a href="#fnref:1" class="footnote-back-ref">↩</a></p></li>
<li id="fn:2"><p>Petrov, Nikolay V.; Sergei S. Nalegaev; Andrei V. Belashov; Igor A. Shevkunov; Sergei E. Putilin; Yu-Chih Lin; Chau-Jern Cheng (2018). "Time-resolved inline digital holography for the study of noncollinear degenerate phase modulation". Optics Letters. 43 (15): 3481. Bibcode:2018OptL...43.3481P. doi:10.1364/OL.43.003481. PMID 30067690. S2CID 51893588. <a href="https://www.researchgate.net/publication/326424496" target="_blank">https://www.researchgate.net/publication/326424496</a> <a href="#fnref:2" class="footnote-back-ref">↩</a></p></li>
</ol>

Cross-phase modulation open-in-new

Cross-phase modulation