Cavity-Ringdown (CRD) Reflectometer and Loss Meter
Our reflectometer GLACIER uses the extreme sensitivity of cavity ring-down spectroscopy to quantify the losses of advanced optical coatings down to 5 ppm. As a typical application the device can characterize supra-mirrors with up to 99.9995% reflectivity. Conventional absorption and reflection measurements are not sufficiently sensitive to quantify today´s super-reflective mirror coatings and are typically limited to the >1000 ppm range (corresponding to <99.9% reflectivity).
Cavity ring-down spectroscopy measures optical losses by the decay of the energy stored inside a cavity.
The technique reaches unrivalled sensitivity because the losses are experienced over and over again after every round trip inside the cavity. Smaller losses lead to longer intra-cavity dwell time thereby automatically increasing the measurement precision. The device features high-speed data acquisition and allows to record measurements within seconds.
It is delivered complete with a computer and a user-friendly software interface for acquisition and real-time analysis
Key Product Features
Reflectivity measurements
Reflectivities up to 99.9995%
Various angles of incidence: 5° - 45° (and 0°)
s and p polarization (separately)
Antireflective coating characterization: Reflectivity down to 0.0005% (5 ppm)
Simple and reproducible alignment: for 0.5", 1" and 2" optics
Spring-loaded mirror fixtures for reproducible mounting without strain
Computer and user-friendly software interface included
High-speed data acquisition and real-time analysis: Complete measurement and analysis within seconds
Available wavelengths:
375 - 1550 nm
other wavelenghts are available upon request
Standard Footprint: 90 x 45 cm2 (standard size)
A family of GLACIERs to choose from. Pick the one that suits your needs best:
GLACIER
GLACIER-123
GLACIER-C
Number of wavelengths
One
Three
Three*
Maximum number of wavelengths
Three
Four
Unlimited!
Possible to add more wavelengths at a later point
Yes**
Yes**
Yes
Wavelength range
375 — 1550 nm
(diode laser based)355, 532 and 1064 nm
4th wavelength:
diode laser based
(375 — 1550 nm)450 — 2000 nm
(freely selected)Laser source
Diode laser
Microchip laser
Supercontinuum with monochromator
Footprint
90 x 45 cm2
90 x 55 cm2 for more
than 1 wavelength90 x 55 cm2
90 x 55 cm2
Reflectivity measurements
Reflectivities up to 99.9995%
Antireflective coating characterization
Reflectivity down to 0.0005% (5 ppm)
Angle of incidence
5° - 45° and 0°
Polarization
s and p (separately)
Optics size
0.5", 1"
(2” and more upon request)Software
Computer and user-friendly software interface included
*Included in the basic version, more can be added.
**Factory upgrade required. For GLACIER, a bigger footprint should be considered in advance (90 x 55 cm2).
Working Principle:
Glacier uses the principle of reflectivity/loss measurements with cavity ring-down spectroscopy based on very low losses at each mirror bounce. The laser pulses travel inside a cavity experiencing optical losses over and over again during each round trip.
Sketch of the working principle of GLACIER, measurement and fitting procedure.
The device measures the time-dependent intensity I(t) leaked through an end mirror of the cavity (center).
The signal decays with a time constant depending on the intra-cavity losses and can be fitted to the following exponential function:
The time constant τ is inversely proportional to the optical losses (1-R) of the cavity with total reflectivity R:
where n is the refractive index, c is the speed of light, and l is the cavity length.
Sample Measurement:
Typical GLACIER measurement of an ultrahigh- reflective mirror for 1030 nm. To obtain the data, the cavity losses with and without the sample were measured and subtracted.This provides an absolute measurement of the test mirror.
商品属性 [波长] 375 — 1550 nm