Physical Optics and Electronics Group
Prof. Rajeev Ram

Major Research Themes:

Silicon Photonic Integration


CMOS Photonics: Develop advanced photonic devices in CMOS and beyond-CMOS materials systems. Systems ranging from high-speed signal processing to processor interconnects are being explored.

Facilities

Group members use Microsystems Technology Laboratories clean rooms for silicon devices. These facilities include a complete 6" CMOS wafer fab. In addition, we work closely with MIT faculty pursuing CVD growth of SiGe materials.

Team

Amir Atabaki, Zheng Li

Publications

  1. Sun, C., M. Georgas, J. Orcutt, B. Moss, Y.-H. Chen, J. Shainline, M. Wade, K. Mehta, K. Nammari, E. Timurdogan, D. Miller, O. Tehar-Zahav, Z. Sternberg, J. Leu, J. Chong, R. Bafrali, G. Sandhu, M. Watts, R. Meade, M. Popovic, R. Ram, V. Stojanovic. IEEE J. of Solid-State Circuits 50.4 (2015): 828-844
    DOI: 10.1109/JSSC.2014.2382101 [PDF]
  2. Karan K. Mehta, Jason S. Orcutt, Jeffrey M. Shainline, Ofer Tehar-Zahav, Zvi Sternberg, Roy Meade, Miloš A. Popović, and Rajeev J. Ram. “Polycrystalline Silicon Ring Resonator Photodiodes in a Bulk Complementary Metal-Oxide-Semiconductor Process.” Optics Letters 39, 4 (2014): 1061-4). [PDF]
  3. Mehta, Karan, Jason Orcutt, Ofer Tehar-Zahav, Zvi Sternberg, Reha Bafrali, Roy Meade, and Rajeev Ram. “High-Q CMOS-Integrated Photonic Crystal Microcavity Devices.” Nature Scientific Reports 4, 4077 (2014). [PDF]
  4. Shainline, Jeffrey M., Jason S. Orcutt, Mark T. Wade, Kareem Nammari, Ofer Tehar-Zahav, Zvi Sternberg, Roy Meade, Rajeev J. Ram, Vladimir Stojanović, and Miloš A. Popović. “Depletion-Mode Polysilicon Optical Modulators in a Bulk Complementary Metal-Oxide Semiconductor Process.” Optics Letters 38.15 (2013): 2729-31. [PDF]
  5. Shainline, Jeffrey M., Jason S. Orcutt, Mark T. Wade, Kareem Nammari, Benjamin Moss, Michael Georgas, Chen Sun, Rajeev J. Ram, Vladimir Stojanović, and Miloš A. Popović. “Depletion-Mode Carrier-Plasma Optical Modulator in Zero-Change Advanced CMOS.” Optics Letters 38 (2013): 2657-9. [PDF]
  6. Georgas, M., J. Orcutt, R. J. Ram, and V. Stojanovic. “A Monolithically-Integrated Optical Receiver in Standard 45-nm SOI.” IEEE J. Solid-State Circuits 47.7 (2012): 1693-1702. [PDF]
  7. Orcutt, Jason S., Benjamin Moss, Chen Sun, Jonathan Leu, Michael Georgas, Jeffrey Shainline, Eugen Zgraggen, Hanqing Li, Jie Sun, Matthew Weaver, Stevan Urošević, Miloš Popović, Rajeev J. Ram, and Vladimir Stojanović. “Open Foundry Platform for High-Performance Electronic-Photonic Integration.” Optics Express 20.11 (2012): 12222-32. [PDF]
  8. Orcutt, Jason S., Sanh D. Tang, Steve Kramer, Karan Mehta, Hanqing Li, Vladimir Stojanović, and Rajeev J. Ram. “Low-Loss Polysilicon Waveguides Fabricated in an Emulated High-Volume Electronics Process.” Optics Express 20.7 (2012): 7243-54. [PDF]
  9. Khilo, Anatol, Steven J. Spector, Matthew E. Grein, Amir H. Nejadmalayeri, Charles W. Holzwarth, Michelle Y. Sander, Marcus S. Dahlem, Michael Y. Peng, Michael W. Geis, Nicole A. DiLello, Jung U. Yoon, Ali Motamedi, Jason S. Orcutt, Jade P. Wang, Cheryl M. Sorace-Agaskar, Miloš A. Popović, Jie Sun, Gui-Rong Zhou, Hyunil Byun, Jian Chen, Judy L. Hoyt, Henry I. Smith, Rajeev J. Ram, Michael Perrott, Theodore M. Lyszczarz, Erich P. Ippen, and Franz X. Kärtner. “Photonic ADC: Overcoming the Bottleneck of Electronic Jitter.” Optics Express 20.4 (2012): 4454-69. [PDF]
  10. Orcutt, J. S., and R. J. Ram. “Photonic Device Layout Within the Foundry CMOS Design Environment.” IEEE Photon. Technol. Lett. 22.8 (2010): 544-6. [PDF]

  11. Orcutt, J. S., Anatol Khilo, Charles W. Holzwarth, Milos A. Popović, Hanqing Li, Jie Sun, Thomas Bonifield, Randy Hollingsworth, Franz X. Kärtner, Henry I. Smith, Vladimir Stojanović, and Rajeev J. Ram. “Nanophotonic Integration in State-of-the-Art CMOS Foundries.” Optics Express 19 (2011): 2335-46. [PDF]

  12. Batten, C., A. Joshi, J. Orcutt, A. Khilo, B. Moss, C. W. Holzwarth, M. A. Popovic, Hanqing Li, H. I. Smith, J. L. Hoyt, F. X. Kartner, R. J. Ram, V. Stojanovic, and K. Asanovic. “Building Many-Core Processor-to-DRAM Networks with Monolithic CMOS Silicon Photonics.” IEEE Micro 29.4 (2009): 8-21. [PDF]

  13. Holzwarth, C. W., R. Amatya, M. Dahlem, A. Khilo, F. X. Kartner, E. P. Ippen, R. J. Ram, and H. I. Smith. “Fabrication Strategies for Filter Bands Based on Microring Resonator.” Journal of Vacuum Science and Technology B 26.6 (2008): 2164. [PDF]

  14. Amatya, R., C. W. Holzwarth, H. I. Smith, and R. J. Ram. “Precision Tunable Silicon Compatible Microring Filters.” IEEE Photon. Technol. Lett. 20.20 (2008): 1739. [PDF]

  15. Barwicz, T., H. Byun, F. Gan, M. Geis, M. Grein, C. W. Holzwarth, J. L. Hoyt, E. P. Ippen, F. X. Kärtner, T. Lyszczarz, O. O. Olubuyide, J. S. Orcutt, M. A. Popovi, P. T. Rakich, R. J. Ram, H. I. Smith, S. Spector, V. Stojanovic, M. R. Watts, and J. U. Yoon. “Silicon Photonics for Compact, Energy Efficient Interconnects.” Journal of Optical Networking 6.1 (2007): 63-72. [PDF]

  16. Groenert, M. E., C. W. Leitz, A. J. Pitera, V. Yang, H. L. T. Lee, R. J. Ram, and E. A. Fitzgerald. “Monolithic Integration of Room-Temperature cw GaAs/AlGaAs Lasers on Si Substrates via Relaxed Graded GeSi Buffer Layers.” Journal of Applied Physics 93.1 (2003): 362-7. [PDF]

  17. Groenert, M. E., A. J. Pitera, R. J. Ram, and E. A. Fitzgerald. “Improved Room-Temperature Continuous Wave GaAs/AlGaAs and InGaAs/GaAs/AlGaAs Lasers Fabricated on Si Substrates via Relaxed Graded GexSi1-x Buffer Layers.” Journal of Vacuum Science and Technology B 21.3 (2003): 1064-9. [PDF]

Publications

  1. Z. Li, J. Xue, M. de Cea, J. Kim, H. Nong, D. Chong, K. Yong Lim, E. Quek, & R. J. Ram, "A sub-wavelength Si LED integrated in a CMOS platform," Nature Communications 14, no. 1 (2023): 882, DOI: https://doi.org/10.1038/s41467-023-36639-1 [PDF]
  2. I. Kang, M. de Cea, J. Xue, Z. Li, G. Barbastathis, & R. J. Ram, "Simultaneous spectral recovery and CMOS micro-LED holography with an untrained deep neural network," Optica 9, no. 10 (2022): 1149-1155, DOI: https://doi.org/10.1364/OPTICA.470712 [PDF]
  3. J. Xue , J. Kim, A. Mestre, K. M. Tan, D. Chong, S. Roy, H. Nong, K. Y. Lim, D. Gray, D. Kramnik, A. Atabaki, E. Quek, & R. J. Ram, "Low-Voltage, High-Brightness Silicon Micro-LEDs for CMOS Photonics," IEEE Transactions on Electron Devices, vol 68, Issue 8 (2021): 3870 - 3875, DOI: https://doi.org/10.1109/TED.2021.3085541 [PDF]
  4. M. de Cea, A. H. Atabaki, & R. J. Ram, "Energy harvesting optical modulators with sub-attojoule per bit electrical energy consumption," Nature, Nature Communications 12 (2021): 2326, DOI: https://doi.org/10.1038/s41467-021-22460-1 [PDF]
  5. M. de Cea, D. Van Orden, J. Fini, M. Wade, & R. J. Ram, "High-speed, zero-biased silicon-germanium photodetector," APL Photonics, vol 6, issue 4 (2021): 041302 , DOI: https://doi.org/10.1063/5.0047037 [PDF]
  6. M. de Cea, E. E. Wollman, A. H. Atabaki, D. J. Gray, M. D. Shaw & R. J. Ram, "Photonic Readout of Superconducting Nanowire Single Photon Counting Detectors," Nature, Scientific Reports, 10 (2020): 9470, DOI: https://doi.org/10.1038/s41598-020-65971-5 [PDF]
  7. M. de Cea, A. H. Atabaki, & R. J. Ram, "Power handling of silicon microring modulators," Opt. Express 27 (2019): 24274-24285 , DOI: https://doi.org/10.1364/OE.27.024274 [PDF]
  8. V. Stojanović, R. J. Ram, M. Popović, S. Lin, S. Moazeni, M. Wade, C. Sun, L. Alloatti, A. H. Atabaki, F. Pavanello, N. Mehta, & P. Bhargava, "Monolithic silicon-photonic platforms in state-of-the-art CMOS SOI processes," Optics Express, Vol. 26, No. 10 (2018) DOI: https://doi.org/10.1364/OE.26.013106 [PDF]
  9. A. H. Atabaki, S. Moazeni, F. Pavanello, H. Gevorgyan, J. Notaros, L. Alloatti, M. T. Wade, C. Sun, S. A. Kruger, H. Meng, K. Al Qubaisi, I. Wang, B. Zhang, A. Khilo, C. V. Baiocco, M. A. Popović, V. M. Stojanović & R. J. Ram, "Integrating photonics with silicon nanoelectronics for the next generation of systems on a chip," Nature, 556 (2018): 349-354, DOI: https://doi.org/10.1038/s41586-018-0028-z [PDF]
  10. S. Moazeni, S. Lin, M. Wade, L. Alloatti, R. J. Ram, & M. Popović, V. Stojanović, "A 40-Gb/s PAM-4 Transmitter Based on a Ring-Resonator Optical DAC in 45-nm SOI CMOS," IEEE Journal of Solid-State Circuits Vol: 52, Issue 12, Dec 2017 (2017) DOI: 10.1109/JSSC.2017.2748620 [PDF]
  11. A. Atabaki, H. Meng, L. Alloatti, K. Mehta, & R. J. Ram, "High-speed polysilicon CMOS photodetector for telecom and Datacom," Applied Physics Letters (2016): 109, 111106 (2016), DOI: 10.1063/1.4962641 [PDF]
  12. L. Alloatti, & R. J. Ram, "Infrared vertically-illuminated photodiode for chip alignment feedback," AIP Advances (2016): 6, 085219 (2016), DOI: 10.1063/1.4961949 [PDF]
  13. L. Alloatti, D. Cheian, & R. J. Ram, "High-speed modulator with interleaved junctions in zero-change CMOS photonics," Applied Physics Letters, 108, 131101 (2016) DOI: 10.1063/1.4944999 [PDF]
  14. L. Alloatti, S. A. Srinivasan, J. S. Orcutt, & R. J. Ram, "Waveguide-coupled detector in zero-change complementary metal–oxide–semiconductor," Appl. Phys. Lett. 107, 041104 (2015) DOI: http://dx.doi.org/10.1063/1.4927393 [PDF]
  15. C. Sun, M. Wade, M. Georgas , S. Lin , L. Alloatti , B. Moss , R. Kumar, A. H. Atabaki , F. Pavanello , R. J. Ram , M. Popović , & V. Stojanović , "A 45nm SOI Monolithic Photonics Chip-to-Chip Link with Bit-Statistics-Based Resonant Microring Thermal Tuning," VLSI Symposium (2015) [PDF]
  16. L. Alloatti, M. Wade, V. Stojanovic, M. Popovic, & R. J. Ram, "Photonics design tool for advanced CMOS nodes," IET Optoelectronics, Vol. 9, Iss. 4, (2015): 163–167, DOI: 10.1049/iet-opt.2015.0003 [PDF]
  17. C. Sun, M. Georgas, J. Orcutt, B. Moss, Y.-H. Chen, J. Shainline, M. Wade, K. Mehta, K. Nammari, E. Timurdogan, D. Miller, O. Tehar-Zahav, Z. Sternberg, J. Leu, J. Chong, R. Bafrali, G. Sandhu, M. Watts, R. Meade, M. Popovic, R. J. Ram, & V. Stojanovic, "A Monolithically-Integrated Chip-to-Chip Optical Link in Bulk CMOS," IEEE J. of Solid-State Circuits 50.4 (2015): 828-844, DOI: 10.1109/JSSC.2014.2382101 [PDF]
  18. K. K. Mehta, J. S. Orcutt, J. M. Shainline, O. Tehar-Zahav, Z. Sternberg, R. Meade, M. A. Popović, & R. J. Ram, "Polycrystalline Silicon Ring Resonator Photodiodes in a Bulk Complementary Metal-Oxide-Semiconductor Process," Optics Letters 39, 4 (2014): 1061-4, [PDF]