Researchers at the Joint Quantum Institute (JQI) have unveiled new photonic chips capable of converting a single color of laser light into multiple hues without the need for active inputs. This breakthrough, reported in the journal Science on November 6, 2025, addresses a longstanding challenge in photonics, which is the development of compact light sources that can be integrated into existing technology.
The demand for effective light manipulation in scientific and industrial applications has surged, creating a global market valued at hundreds of billions of dollars. Traditional light sources often require bulky equipment, making them less suitable for compact applications. The newly developed chips not only simplify the process but also expand the potential for quantum computing and precision measurements.
Advancements in Photonic Technology
The photonic devices designed by the JQI team are not just enhanced versions of existing solutions. Unlike prisms that merely split light into existing colors, these chips generate entirely new wavelengths, enabling wider applications in technology fields. The chips create second, third, and fourth harmonics from a standard frequency of 190 THz, commonly used in telecommunications.
Mohammad Hafezi, a JQI Fellow and professor at the University of Maryland, emphasized the significance of this advancement, stating, “Our team has taken a significant step toward overcoming limitations in integrated photonics as an on-chip light source.” The new design eliminates the need for complex optimization, making these photonic chips more versatile and reproducible.
One key to this success lies in the chips’ structure. The researchers utilized an array of resonators that facilitate nonlinear interactions. Unlike linear interactions, where light merely bends or is absorbed, nonlinear interactions can change the frequency of light itself. This process has been refined over decades, allowing for the effective generation of new light frequencies.
Overcoming Challenges in Nonlinear Interactions
Historically, nonlinear optical processes have been weak, making them difficult to harness for practical applications. Initial observations of these phenomena, such as second harmonic generation, were often dismissed due to their subtlety. The JQI team has built on previous research to enhance the strength of these interactions through innovative design.
The challenge for researchers has been balancing the requirements for frequency-phase matching. This involves ensuring that the original and new frequencies generated by a resonator align perfectly to maintain efficiency. Small variations in chip design can disrupt this delicate balance.
Lead author Mahmoud Jalali Mehrabad, now a research scientist at MIT, highlighted the complexity of achieving simultaneous harmonic generation. The development of multiple resonators working together has emerged as a solution to boost nonlinear effects without the need for intricate tuning.
The team’s recent findings indicate that their two-timescale resonator arrays can reliably generate harmonics across various chips. By allowing light to circulate at different speeds, these devices effectively create the necessary conditions for frequency-phase matching without manual adjustments.
The implications of this breakthrough are significant. Researchers anticipate that these photonic chips will enhance applications in metrology, frequency conversion, and nonlinear optical computing, all while simplifying the design process. As Mehrabad noted, “We have simultaneously relaxed these alignment issues to a huge degree, and also in a passive way.”
The JQI team, which includes several notable researchers, has made strides toward addressing long-standing challenges in the field of photonics. Their work not only opens new avenues for research but also positions photonic chips as a key technology for the future.
