article published Franz Roeder author 88149 René Pollmann author 78890 Viktor Quiring author Christof Eigner author 13244https://orcid.org/0000-0002-5693-3083 Benjamin Brecht author 271500000-0003-4140-0556 Christine Silberhorn author 26263 15 department 623 department 288 department <jats:p> The development of practical sensors for optical coherence tomography (OCT) with undetected photons requires miniaturization via integration. To be practical, these sensors must exhibit a large spectral bandwidth and a high brightness, which are linked to a high axial resolution and a sufficient signal-to-noise ratio, respectively. Here, we combine these requirements in a scheme for OCT measurements with undetected photons based on nonlinear <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"> <a:mi>Ti</a:mi> <a:mo>:</a:mo> <a:msub> <a:mrow> <a:mi>Li</a:mi> <a:mi>Nb</a:mi> <a:mi mathvariant="normal">O</a:mi> </a:mrow> <a:mn>3</a:mn> </a:msub> </a:math> waveguides. We investigate the performance benchmarks of the commonly used SU(1,1) scheme in comparison to an induced-coherence scheme and find that the latter is actually better suited when implementing measurements with undetected photons in integrated systems. In both schemes, we perform pump-gain optimization and OCT measurements with undetected photons with an axial resolution as low as <d:math xmlns:d="http://www.w3.org/1998/Math/MathML" display="inline"> <d:mn>28</d:mn> <d:mspace width="0.2em"/> <d:mtext fontfamily="times">μ</d:mtext> <d:mrow> <d:mi mathvariant="normal">m</d:mi> </d:mrow> </d:math> . </jats:p> American Physical Society (APS)2026 eng 2331-701910.1103/cwsx-42c4 253 Roeder F, Pollmann R, Quiring V, Eigner C, Brecht B, Silberhorn C. Toward integrated sensors for optimized optical coherence tomography with undetected photons. <i>Physical Review Applied</i>. 2026;25(3). doi:<a href="https://doi.org/10.1103/cwsx-42c4">10.1103/cwsx-42c4</a> @article{Roeder_Pollmann_Quiring_Eigner_Brecht_Silberhorn_2026, title={Toward integrated sensors for optimized optical coherence tomography with undetected photons}, volume={25}, DOI={<a href="https://doi.org/10.1103/cwsx-42c4">10.1103/cwsx-42c4</a>}, number={3034031}, journal={Physical Review Applied}, publisher={American Physical Society (APS)}, author={Roeder, Franz and Pollmann, René and Quiring, Viktor and Eigner, Christof and Brecht, Benjamin and Silberhorn, Christine}, year={2026} } Roeder, Franz, et al. “Toward Integrated Sensors for Optimized Optical Coherence Tomography with Undetected Photons.” <i>Physical Review Applied</i>, vol. 25, no. 3, 034031, American Physical Society (APS), 2026, doi:<a href="https://doi.org/10.1103/cwsx-42c4">10.1103/cwsx-42c4</a>. Roeder, Franz, René Pollmann, Viktor Quiring, Christof Eigner, Benjamin Brecht, and Christine Silberhorn. “Toward Integrated Sensors for Optimized Optical Coherence Tomography with Undetected Photons.” <i>Physical Review Applied</i> 25, no. 3 (2026). <a href="https://doi.org/10.1103/cwsx-42c4">https://doi.org/10.1103/cwsx-42c4</a>. F. Roeder, R. Pollmann, V. Quiring, C. Eigner, B. Brecht, C. Silberhorn, Physical Review Applied 25 (2026). Roeder, F., Pollmann, R., Quiring, V., Eigner, C., Brecht, B., &#38; Silberhorn, C. (2026). Toward integrated sensors for optimized optical coherence tomography with undetected photons. <i>Physical Review Applied</i>, <i>25</i>(3), Article 034031. <a href="https://doi.org/10.1103/cwsx-42c4">https://doi.org/10.1103/cwsx-42c4</a> F. Roeder, R. Pollmann, V. Quiring, C. Eigner, B. Brecht, and C. Silberhorn, “Toward integrated sensors for optimized optical coherence tomography with undetected photons,” <i>Physical Review Applied</i>, vol. 25, no. 3, Art. no. 034031, 2026, doi: <a href="https://doi.org/10.1103/cwsx-42c4">10.1103/cwsx-42c4</a>. 650942026-03-23T12:28:33Z2026-03-25T07:59:04Z