Integrated chip design and nanofabrication
Chip-based source for imaging and sensing
Photonic chip-based quantum storage
Narrow linewidth lasers
Nonlinear optics
 
I am always looking for self-motivated students who are interested in pursuing Master's or Ph.D. degrees in the broad areas of optics and photonics. Please send me an email if you are interested.

Journals:

1. X. Ji, D. Mojahed, Y. Okawachi, A. L. Gaeta, C. P. Hendon, and M. Lipson, “Millimeter-scale chip-based supercontinuum generation for optical coherence tomography”, Science Advances 7, eabg8869 (2021). (IF: 14.136 JCR: Q1)

2. X. Ji, J. K. Jang, U. D. Dave, C. Joshi, M. C. Zanarella, A. L. Gaeta, and M. Lipson, “Exploiting ultralow multimode waveguides for broadband frequency combs”, Laser & Photonics Reviews 15 (1), 2000353 (2021). (IF: 13.138 JCR: Q1)

3. X. Ji, S. P. Roberts, M. C. Zanarella and M. Lipson, “Methods to Achieve Ultra-high Quality Factor Silicon Nitride Resonators”, APL Photonics 6, 071101 (2021). (Featured Article) (IF: 5.672 JCR: Q1)

4. X. Ji, X. Yao, Y. Gan, A. Mohanty, M. Tadayon, C. P. Hendon, and M. Lipson, “On-chip tunable photonic delay line”, APL Photonics 4, 090803 (2019). (Featured Article) (IF: 5.672 JCR: Q1)

5. X. Ji, X. Yao, A. Klenner, Y. Gan, A.L. Gaeta, C. P. Hendon, and M. Lipson, “Chip-based frequency combs sources for optical coherence tomography,” Optics Express 27, 19896-19905 (2019). (IF: 3.894 JCR: Q1)

6. X. Ji, F. A. S. Barbosa, S. P. Roberts, A. Dutt, J. Cardenas, Y. Okawachi, A. Bryant, A. L. Gaeta, and M. Lipson, “Ultra-low-loss on-chip resonators with sub-milliwatt parametric oscillation threshold,” Optica 4, 619-624 (2017). (ESI Highly Cited Paper). (IF: 11.104 JCR: Q1)

7. B. Stern, X. Ji, Y. Okawachi, A. L. Gaeta, and M. Lipson, “Battery-operated integrated frequency comb generator,” Nature 562, 401-405 (2018). (ESI Highly Cited Paper) (IF: 49.962 JCR: Q1)

 
Conferences:

1. X. Ji, D. Mojahed, Y. Okawachi, A. L. Gaeta, C. P. Hendon, and M. Lipson, "Millimeter-Scale Chip-Based Supercontinuum Generation for Optical Coherence Tomography," in Conference on Lasers and Electro-Optics, OSA Technical Digest (Optical Society of America, 2021), paper STh1H.6.

2. X. Ji, J. K. Jang, U. D. Dave, C. Joshi, M. C. Zanarella, A. L. Gaeta, M. Lipson, "Ultra-Low Threshold Broadband Soliton Frequency Comb Generation," in Conference on Lasers and Electro-Optics, OSA Technical Digest (Optical Society of America, 2020), paper SW3J.6.

3. X. Ji, S. P. Roberts, and M. Lipson, "High Quality Factor PECVD Si3N4 Ring Resonators Compatible with CMOS Process," in Conference on Lasers and Electro-Optics, OSA Technical Digest (Optical Society of America, 2019), paper SM2O.6.

4. X. Ji, A. Klenner, X. Yao, Y. Gan, A. L. Gaeta, C. P. Hendon and M. Lipson, “Chip-Based Frequency Combs for High-Resolution Optical Coherence Tomography”, in Conference on Lasers and Electro-Optics, OSA Technical Digest (online) (Optical Society of America, 2018), paper STh1J.4.

5. X. Ji, X. Yao, M. A. Tadayon, A. Mohanty, C. P. Hendon, and M. Lipson, "High Confinement and Low Loss Si₃N₄ Waveguides for Miniaturizing Optical Coherence Tomography," in Conference on Lasers and Electro-Optics, OSA Technical Digest (online) (Optical Society of America, 2017), paper SM3C.4.

6. X. Ji, F. A. Barbosa, A. Bryant, J. Cardenas, S. P. Roberts, and M. Lipson, "High Quality Factor Si₃N₄ Ring Resonators Achieved by Surface Roughness Reduction," in Conference on Lasers and Electro-Optics, OSA Technical Digest (2016) (Optical Society of America, 2016), paper SM2R.3.
    

Patents:

1. Microresonator-Frequency-Comb-Based Platform For Clinical High-Resolution Optical Coherence Tomography. United States Patent No. 11,092,424 (Issued on August 17, 2021)

2. Thermally Tunable Low Loss Broadband Waveguides and Related systems and Methods. US Patent App. 16/480,973.

3. Compact Narrow-linewidth Integrated Laser. US Patent App. 16/651,673

4. Fully Integrated Chip Platform for Electrically Pumped Frequency Comb Generation. United States Provisional Application No 62/650,086 (Filed on March 29, 2018)

5. Tunable Optical Frequency Comb Generator in Microresonators. United States Provisional Application No. 62/804,613 (Filed on February 12, 2019)

6. Self-Injection Locking of Fabry-Perot Lasers with Silicon based Resonators for High Power Narrow Linewidth on Chip Sources. United States Provisional Application No. 62/820,136 (Filed on March 18, 2019)