Author: Ori levin
At Raicol, as a world leader in the manufacture of PPKTP, our goal is to support the growing quantum industry and drive it forward as much as we can.
To support this goal, Raicol is continuously cooperating with research centers and leading universities worldwide to provide them with advanced quasi-phase-matching crystals that help them accomplish innovative research. At times, this requires us to push the envelope to improve our fabrication techniques and bring new capabilities.
In the past few years, Raicol has been dealing with repeating requests for PPKTP with low absorption, higher pump powers, and requests for shorter poling periods. We found some of these requirements intriguing and challenging and started researching different solutions to tackle these issues.
One of the leading challenges our customers face is dealing with gray tracking.
Gray tracking is a phenomenon where optical beams, above the average power threshold, propagate through PPKTP crystal and create photorefractive damage that leaves opaque areas, making the crystal useless.
In unpolled KTP which is used for nonlinear conversions, Raicol solved this issue by developing the HGTR KTP which was designed to support much higher power densities, however, HGTR KTP cannot be easily polled, thus does not offer a solution for the quantum industry.
To tackle this problem, Raicol has started a research project to develop a new product that will support a higher power-frequency conversion process
(such as SPDC) but at the same time, will not compromise the PPKTP absorption parameters. During the research, we have emphasized optimizing the Raicol bulk KTP absorption.
Following two years of research, Raicol developed a version of HGRK KTP that can be polled and created the new version of ppKTP which we called SPPKTP. The SppKTP supports up to 6 times the power as a standard PPKTP and has about 40% less absorption (ppm) in the 532 nm wavelength .
This technology finds numerous applications where even the smallest optical losses are highly detrimental or systems that can benefit from higher powers than typical KTP can support. Key examples include Optical Parametric Oscillators (OPOs), squeezed light sources, Quantum communications and quantum encryption (QKD), and high-power laser systems, where the high circulating power within the optical cavity demands an elevated optical damage threshold, exceptional crystal purity, and minimal losses to maintain efficient frequency conversion. In such systems, even minute losses can lead to reduced performance, thermal effects, and beam quality degradation.
In contrast, there are also applications operating at low power but requiring extremely low optical losses, such as systems with high Q-factor optical cavities. Here, losses directly influence the cavity linewidth, with narrow linewidths being essential for applications in high-precision metrology, laser stabilization, and quantum technologies.
Raicol’s SPPKTP crystals represent a significant advancement in nonlinear optical materials, driving innovation across diverse areas of photonics technology. Their breakthrough properties help unlock new possibilities in the field, from quantum applications to high-power laser systems
For detailed information about our sPPKTP crystals, download our product brochure or reach out to our team.
Have you already subscribed to our YouTube channel? Don’t miss out—subscribe now for exclusive content and updates from our company.
