fiber-based confocal microscope for transmission

2 fiber-based low temperature objectives

confocal transmission at cryogenic temperatures

independent position both objectives in xyz

pump-probe @ large lateral separation (up to 3 mm)

2 independent single mode fiber channels

independent wavelengths for excitation and detection


The attoCFM III is a highly stable, compact cryogenic microscope optimized for both reflection and transmission measurements. The attoCFM III confocal microscope is thermally compensated to guarantee highest stability suitable for spectroscopic measurements over extended periods of time.

Furthermore, combining the attoCFM III with cryogen-free cooling solutions is easily possible, opening up new possibilities in cryogenic long-term investigations while considerably reducing operational costs. The attoCFM III is available with interferometric encoder for closed loop operation.

In the attoCFM III, a laser beam is coupled into the first arm of a single mode optical fiber coupler. The end of the fiber connected to the second arm of the fiber coupler is glued into a ceramic ferrule. The laser light guided through this fiber illuminates the sample while the single mode fiber itself plays the role of the blocking pinhole aperture when collecting the scattered reflected light from the sample. The intensity of this scattered light is measured by a detector connected to the fourth arm of the fiber coupler. A second, low-temperature compatible confocal objective underneath the sample is used for transmission measurements. The transmitted light collected by the objective is guided to an additional detector using a separate single mode fiber. For more info please refer to the fundamentals section.

Cryogenic Tablet


Suitable Cooling Systems
titanium housing diameter47 mm
bore size requirementdesigned for a 2" (50.8 mm) cryostat/magnet bore
compatible cryostatsattoDRY1000/1100/2100, attoLIQUID1000/2000 (attoLIQUID3000/5000 on request)
General Specifications
type of instrumentfiber optics based confocal microscope for transmission measurements
sensor head specifics2 independent fiber-coupled low temperature compatible aspheric objectives for ultimate stability
Compatibility with Electronics
scan controller and softwareASC500 basic (for detailed specifications please see attoCONTROL section)
laserLDM600 laser/detector module (for detailed specifications please see attoCONTROL section)
Confocal Unit
configurationone fiber-coupled LT objective for excitation, one fiber-coupled LT objective for detection
key benefitsultra-stable longterm transmission measurements & independent wavelengths for excitation & detection
pinhole configurationpinhole provided by single mode fiber core
pinhole sizedependent on fibers, typically 3 .. 9 µm mode field diameter
compatible LT-objectiveLT-IWDO, LT-LWDO (see accessory section for more information)
Options and Upgrades
closed loop upgrade for coarse positionersincl. for both objectives
excitation wavelength rangelimited to wavelength range of single mode fiber, default 650 nm (others on request)
illumination port specificationFC/ APC-connector for single mode fiber
detection modee.g. transmission, reflection, luminescence, fluorescence
detection wavelength rangelimited to wavelength range of single mode fiber, default: 650 nm (others on request)
detection port specificationFC/ APC-connector for single mode fiber
Sample Positioning
total travel rangeindependent degrees of freedom for both LT-objectives 5 x 5 x 5 mm³ (open loop) with fixed sample
step size0.05..3 µm @ 300 K, 10..500 nm @ 4 K
fine scan range50 x 50 µm² @ 300 K, 30 x 30 µm² @ 4 K (open loop)
sample holderTi plate with aperture of 8 mm in diameter with integrated heater and calibrated temperature sensor
Suitable Operating Conditions
temperature range1.5 K..300 K (dependent on cryostat); mK compatible setup available on request
magnetic field range0..15 T+ (dependent on magnet)
operating pressuredesigned for He exchange gas (vacuum compatible version down to 1E-6 mbar on request)
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