New Products: Enhanced Cooling, High-Density Flex Wiring, and LD400sl
We are proud to announce the next leap forward for our cryogenic measurement systems with a significant increase in cooling power, and a new wiring platform that provides more signal lines in a new form factor. These developments will enable quantum computing applications to scale further, and allow more complex cryogenic measurement infrastructure to be fitted into our systems.
Our enhanced cooling solution optimizes the integration of pulse tube cryocoolers in our dilution refrigerators. This improved integration brings a significant increase in cooling power at the 4K flange, doubling the amount of cooling power at 3 K. The solution also allows elevated 4K flange temperatures during normal operation up to 5 K, delivering up to three times more cooling power.
Today, we are also announcing High-Density Flex Wiring (FPC) – our new, cost-effective, high-density wiring platform utilizing flexible printed circuit (FPC) wiring to deliver enhanced wiring capacity for our side-loading systems. Offering up to 240 channels per side-loading port, the all-new solution delivers denser signal lines with reduced thermal load.
Alongside these launches, we are also announcing a new LD System with side-loading ports – the LD400sl – that can take advantage of both the new enhanced cooling integration and High-Density Flex Wiring (FPC).
Enhanced Cooling
Scaling up quantum computers requires an increase in the number of wiring lines carrying signals between the room temperature control electronics and the quantum chips inside the dilution refrigerator. However, the addition of more DC and microwave wiring lines, along with any active electronics, increases the thermal load in the dilution refrigerator. To compensate for the increased heat, additional cooling power is needed, especially at the 4K flange. (Raicu et al., 2025).
Through the collaboration of our R&D teams in Helsinki and Syracuse, we have developed a solution to optimize the integration of Cryomech pulse tube cryocoolers in Bluefors dilution refrigerators to increase their cooling performance. This redesigned integration results in a significant increase in cooling power at the 4K flange.
Enhanced 4K cooling is available immediately for the LD400 System (including the Ultra-Compact LD and side-loading versions of the system) and the XLD1000sl System. There are three pulse tube models available with enhanced 4K cooling: PT415-RM, PT425-RM, and PT310-RM.
When systems with enhanced cooling are operated at 3 K, the available cooling power at the 4K flange doubles. With the enhanced PT310-RM, the LD400 now has 500 mW of available cooling power at the 4K flange at 3 K. In an XLD1000sl equipped with the PT425-RM & PT310-RM combination, there is now 700 mW of cooling power at the 4K flange at 3 K.
The improved pulse tube cryocooler integration also makes it possible to operate the 4K flange at a higher temperature without affecting the dilution unit. Elevated 4K flange temperatures generate a significant increase in available cooling power. The maximum operating temperature of the 4K flange now reaches 5 K with the LD400 System, where it can provide 1500 mW of available cooling power with the enhanced PT425-RM – tripling the amount of cooling power at maximum temperature. With the XLD1000sl, the maximum operating temperature of the 4K flange is ~5 K, where it can now provide 1300-2000 mW of cooling power when the system is equipped with dual PT425-RM configuration.
The enhanced pulse tube integration uses the same space and positioning in the cryostat, so no changes are required to experimental setups. The enhancements made to the pulse tube integration also enable better low-vibration performance and decrease the cooldown time of our systems.
By increasing cooling power at the 4K flange, Bluefors dilution refrigerators can be equipped with more wiring, more active electronics (for example, cryo-CMOS and low-noise amplifiers), larger experimental setups, and deliver colder temperatures for superconducting magnets.
High-Density Flex Wiring (FPC)
Along with enhanced cooling, we are announcing our new high-density wiring solution – High-Density Flex Wiring (FPC). This cost-effective, high-density wiring platform is based on proprietary flexible printed circuit (FPC) technology, providing enhanced wiring capacity for our side-loading systems.
With up to 240 channels available per side-loading port, the all-new solution is based on lossy lines, delivering a reduced thermal load in a compact package. With a frequency range up to 12 GHz, High-Density Flex Wiring is ideal for drive lines for high qubit counts in both superconducting and spin qubit systems. The wiring comes in a continuous form factor, from room temperature to the mixing chamber flange.
High-Density Flex Wiring (FPC) fits into the side-loading ports of Bluefors XLD and LD cryostats, and can be preassembled before installation. The design allows for 1 to 8 FPCs per side-loading port and has a selection of attenuators and filters available. It includes all the necessary components from the room temperature control electronics to the experimental flange, with SMPM connectors at the MXC Flange and SMA connectors at room temperature.
The new wiring platform enables the scaling-up of wiring for quantum computing applications, and has been designed to enable future options for attenuators and filters, increased density, and low-loss lines.
Contact our sales engineers to be among the first to utilize this innovative solution.
Side-Loading LD400 System
Together with enhanced cooling, we are bringing a much-requested feature to our LD Systems – side-loading ports. The LD400sl System matches the performance of our standard LD400 Systems, adding 2 side-loading ports to enable the simple and convenient installation of our measurement infrastructure modules.
With the new enhanced 4 K cooling feature, the LD400sl can now better handle both passive and active heat load from the expanded wiring and cryogenic components enabled by the side-loading port.
The side-loading ports in the LD400sl also make it possible to install our High-Density Flex Wiring (FPC) and High-Density Wiring options in the LD. The side-loading feature is particularly beneficial for complex experiments with higher payloads, or quantum applications with a large number of qubits in a compact cryostat.
Our side-loading measurement infrastructure options are also 100% compatible with our XLD systems, making the LD400sl the ultimate testing system with interchangeable wiring across LD and XLD systems. This makes it easier than ever to scale up experiments from an LD to our larger systems.
The side-loading feature makes it easy to assemble and maintain large wiring infrastructures. Assembly can be prepared on a workbench while the system is running, and immediately exchanged when the system reaches room temperature.
The LD400sl System is available immediately. The side-loading configuration is also available for the Ultra-Compact LD System.
Advanced Solutions for Quantum Applications
This innovative combination of products delivers a holistic cryogenic solution that supports and improves the cooling, wiring, operability and scalability of Bluefors systems.
The improvements achieved with our enhanced cooling pulse tube integration are an example of research & development excellence that is only possible through the collaborative, applied expertise of Bluefors and Cryomech product development teams. Enhanced cooling is a concrete example of the benefits that the combined Bluefors and Cryomech product portfolio brings to customers.
By delivering more cooling power alongside a new high-density wiring solution and new side-loading configuration of our LD System, Bluefors proudly shows its commitment to developing and releasing more advanced solutions for quantum technology applications.
To find out more about all the new products, please contact our sales engineers.