LABORATORY OF FUNDAMENTAL METROLOGY, PRAGUE

8014      Dept. of Quantum Metrology of Length

Subject field: wavelength of laser radiation, length

Head:

Dr. Petr Balling

pballing@cmi.cz

Phone: +420-257 288 326

how to find us

Fax: +420-257 328 077

LEADING LABORATORY IN THE CZECH REPUBLIC IN GIVEN SUBJECT FIELD

Laboratory services:

primary standards -wavelength

interferometry

long gauge blocks

other services

pricing

Primary standards - wavelength:

calibration of laser wavelengths - especially for laser interferometers and iodine stabilized lasers directly by comparison with primary standards realizing SI unit metre or by traceable wavemeters

The femtosecond synthesizer of the comb of optical frequencies MenloSystems FC8004 was installed in CMI-LPM in late 2005. Since then it is used for precise absolute measurement of optical frequencies – hundreds of terahertz – traceable to primary time and frequency standards TAI. (the same time this technique was awarded the Nobel Prize for physics – co-founder of Menlo Systems prof. Th. Hänsch is one of laureates      http://nobelprize.org/nobel_prizes/physics/laureates/2005/index.html )

Working range of the comb is from 520nm to 1065nm, but e.g. frequency of wavelength standard 1542nm is possible to measure through its second harmonic 771nm. All primary wavelength standards 633nm, 543nm, 532nm and 1540..1542nm were successfully measured in CMI in 2006.

Etalons and instruments:

iodine stabilized HeNe lasers 543 nm and 633 nm - national standards of length

iodine stabilized Nd:YAG laser (1064 nm a 532 nm)

acetylene stabilized DFB laser (1542 nm a 771 nm)

all these primary standards were developed in this laboratory, internationally compared with similar standards e.g. in BIPM and all of them absolutely measured by fs-comb with traceability to TAI

other wavelengths from VIS and NIR range are calibrated by wavemeters Burleigh

Used methods:

procedures ČMI: 801-MP-C402, 801-MP-C404, 801-MP-C407

The best measuring capability:

The best measuring capability is stated as expanded uncertainty of measurement for coverage probability 95%.

Measuring quantity or instrument

Range of calibration

Best measuring capability

Identification of method, remarks

vacuum wavelength

633 nm

4.10^-11 rel.

vacuum wavelength

543 nm

1.10^-11 rel.

vacuum wavelength

532nm / 1064 nm

4.10^-12 rel.

vacuum wavelength

771nm / 1542 nm

5.10^-11 rel.

vacuum wavelength

400nm to 1600 nm

2.10^-6 rel.

pulsed 1.10^-5 rel.

Interferometry:

calibration of counting laser interferometers

Etalons and instruments:

interferometric comparator IK-1 is used for combined test of precise displacement measuring instruments - especially laser interferometers. Comparator generates displacement measured simultaneously by instrument to be tested and reference instrument.

Used methods:

procedure ČMI 801-MP-C405

The best measuring capability:

The best measuring capability is stated as expanded uncertainty of measurement for coverage probability 95%.

Measuring quantity or instrument

Range of calibration

Best measuring capability

Identification of method, remarks

laser interferometer calibration

1.5 m

Q[ 0.001 ; 0.1L ] mm*

comparator IK-1

Long gauge blocks:

calibration of long gauge blocks by interferometry

Etalons and instruments:

Long gauge block interferometer for gauges to 1 m length - IDKM - uses radiation of primary wavelength standards delivered by PM fibre and precise system for wavelength compensation (measuring pressure, temperature a humidity of air, CO₂ concentration and temperature of material). IDKM can be used for thermal expansion coefficient measurement.

Used methods:

procedure ČMI 801-MP-C406

The best measuring capability:

The best measuring capability is stated as expanded uncertainty of measurement for coverage probability 95%.

Measuring quantity or instrument

Range of calibration

Best measuring capability

Identification of method, remarks

gauge block - length

0.1 m - 1 m

Q[ 0.07 ; 0.085L ] mm*

interferometer IDKM

thermal expansion coefficient

-10 to +30 ppm/K

Q[0.017/L; 0.006; 0.0008a] ppm/K*

for 15°C to 25°C

Other services:

measurement of optical grating pitch (procedure 801-MP-C408)

calibration of wavemeters and (optical) spectrum analyzers

calibration of precise displacement sensors

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