NIST-SS25-13

6695 / 334516

Title:  Low-noise and low-drift closed-loop cryogenic microscope system, including nanopositioners and cryogenic high-NA optical objective

BACKGROUND

The mission of the Quantum Optics Group of the Quantum Measurement Division is to develop and characterize measurement methods that take advantage of the quantum nature of light to achieve better performance and uncertainties or to enable new applications that are not possible with classical methods and light sources. Therefore, one of the most important aspects of Quantum Measurement Division’s research is to demonstrate a prototype of a high-efficiency deterministic single-photon source in a telecom band. This source is an essential component for quantum communications and for future scalable quantum computer networks. Operation of the source requires a Low-noise and low-drift closed-loop cryogenic microscope system, including nanopositioners and cryogenic high-NA optical objective.

NIST will use the system to accommodate a high-efficiency deterministic single-photon source in telecom C-band, for applications ranging from classical and quantum telecommunication networks, in-situ source recognition and classification, and quantum effects in biological systems. This device shall be optimized for high-efficiency coupling of C-band telecom photons produced by quantum dots. This device will be an integral component in NIST’s Physical Measurement Laboratory’s Quantum Measurement Division’s laboratory. It will be used to study single-photon and entangled light state generation for quantum networks and quantum information science. Light emitted from the quantum dots will be coupled into the fiber for experiments and characterization.

NIST has a need for a low-noise and low-drift closed-loop cryogenic microscope system, including nanopositioners and cryogenic high-NA optical objective that meet or exceed the following draft minimum specifications:

Contract Line-Item Number (CLIN) 0001: The Contractor shall provide a closed-loop helium cryostat with compressor and vacuum pump to include free-space experimental chamber with XYZ nanopositioning stages and high numerical aperture (NA) objective that meet the following minimum specifications:

• Operating Ambient Temperature: between 295 K or less and 305 K or more
• Experimental chamber:
  • Cold stage base temperature ≤ 3.8 K.
  • Temperature Range: 3.8K to 320K (cold plate with no additional stages)
  • Temperature stability < 15 mK peak-to-peak fluctuations with damped sample mount
  • Cooling Power ≥ 170 mW at 5 K or ≥ 130 mW at 4.2 K
  • Cooldown time to 5 K ≤ 4.5 hours.
  • Cold plate vibration stability <5 nm peak-to-peak fluctuation in X, Y,& Z Axis
  • DC Electrical access: ≥ 16 available DC feed-throughs for future ues (i.e. not counting feed-throughs already in use e.g. for nanopositioning stage, temperature monitoring, etc.).
  • RF electrical access: ≥ 2 x RF connections (50 Ohm coaxial, 18 GHz).
  • Nanopositioning stage (see description below) installed.
  • The system includes two fiber optic feedthroughs compatible with SMF-28.
  • At least 5 optical access ports, with two windows (one cold and one warm) on each port. Ports must be reconfigurable to easily replace windows.
  • Free-space optical access: ≥ 5 windows (≥ 25 mm diameter) with <5 % loss at wavelengths from 1450 nm to 1650 nm
  • The system should be deployable to an optical lab with optical tables.
  • Internally housed and vertically mounted microscope objective holder. The holder must be temperature-regulated with a heater and thermometer, allowing the user to select and hold the objective between 250 K – and 310 K throughout the entire duration of the cooldown cycle.
  • The system to include at least two interchangeable sample holders: one with 16 DC wires, and one flat sample holder.
  • The top optical access window must have threaded holes (or set screw holes) that allow for an external fiber coupler mount via Thorlabs 30 mm cage system.
• Objective:
  • ≥0.8 NA objective.
  • Working distance: < 1.3 mm.
  • Optical loss <20% everywhere in the wavelengths range from 1150 nm to 1620 nm.
  • Temperature and pressure compatible with the experimental chamber.
  • Mounted in the experimental chamber using a user-removable mount.
  • Vertical mount compatible.
• Nanopositioning stage:
  • Installed in the experimental chamber – thermally coupled to cold plate.
  • System needs to include integrated cryogenic closed-loop X, Y, and Z Nanopositioners and controller. Each axis equipped with a