C-band Gas Cell:
Acetylene Cells: C2H2-M
Acetylene gas absorption has been widely researched
and identified by national standards bodies as a primary
wavelength reference in the band 1510nm-1540nm.
Move your calibration system to a physical constant. Gascells are inherently NIST traceable, have unparalleledaccuracy, and extremely low drift. Standard pressuresoffered are 20 Torr where the linewidth is about 5pm, 50
Torr matching NIST SRM2517A, 200 Torr matching theNIST SRM2517, and 400 Torr. The line depth given will
only be seen if the instrument (filter resolution or laser
linewidth) can resolve the absorption linewidth. We allow
the acetylene pressure to be tailored to your application

Features
1. With fiber input and output for applications needing optical
output such as a OSA calibrator.
2. Absorption tube (glass only) , 5mm by 30mm
3. With a built in InGaAs photodiode for direct board mount• Hermetic seal, >20 year life

Note: We can also package in a metal instrument housing which isuseful for lab applications and provides bulkhead connectors forconvenience and ruggedness. It can also be filled with HCN gas
instead of acetylene which allows full C-band coverage at reduced line
depth ie approximately 1dB instead of 7dB• Rugged miniaturized package

1Specifications• Wedged windows and coated optics for minimum
interference artifacts• Custom pressure and options• Low cost

Gas Lines:
Wavelength range

nm1510 to 1540

Wavelength Accuracypm±0.3 (1 , 200 Torr, 400 Torr)±0.01 (1 20 Tott)

Temperature dependencepmApplications<0.01/°C

Atmospheric pressure orhumidity dependence

not detectable• Sensor system calibrator

Linewidth2 (-3dB)

nm

0.025 typical (200Torr)• Wavelength calibrator for tunable laser

Acetylene Pressure (25 °C)

Torr

10 to 600 ±10%

• Wavelength calibrator for OSA or tunable filter

Carbon Isotope
Absorption line depth (R9)

12 standard (13 optional)dB

7 typical (200 Torr, 400 Torr )5 typical (20 Torr)

Cell Transmission

%

>50%

Cell Lifetime

years

>20

Operating temperature°C-20 to +80

Storage temperature°C-40 to +100

A/W

>0.5

• Wavelength locker

Ordering Information (example)
C2H2 -12 - M –Photodiode:Net responsivity
Capacitance (0V)pf

Shunt resistance

M>5

1. Specifications subject to change without notice
2. For 200 Torr, 0.05nm for 400 Torr. Minimum linewidth at pressures <20Torr is 0.005nm.
Match pressure to application for best performance

λTorr

Output:Isotope:
Carbon Isotope: 12, 13-None

Pressure:

Size:
Mini: M

50 typicalPD - 200

Photodiode Output: PD
Fiber Output: F
Tube only: T

Connector(s):
FCPC
FCAPC
SCPC
SCAPC
None

Wavelength References
14711 S Buckner Creek Rd
Mulino, OR 97042 USA
Tel: (503) 632-5240 632-5215(fax)
Email: sales@wavelengthreferences.com

Wavelength λ References
R Branch

Wavelength(nm)

P Branch

25
2423
22
21
20
19
18
17
16
15
14
13
12
1110987654
32
11513.2010
1513.5841
1513.9735
1514.3692
1514.7712
1515.1794
1515.5939
1516.0148
1516.4419(1)1516.8754
1517.3151
1517.7612
1518.2136
1518.6723
1519.1373(1)1519.6087
1520.0864
1520.5704
1521.0608(1)1521.5574
1522.0605
1522.5699
1523.0857
1523.6077
1524.1362(1)

12
34
56
7
8
91011
12
13
14
15
16
1718192021
22
23
24
25

Tel: (503) 632-5240 (503) 632-5215(fax)

Wavelength(nm)

Dimensions
M package:

1525.7602
1526.3142
1526.8746(1)1527.4415(1)1528.0147(1)1528.5942(1)1529.1802
1529.7726
1530.3714
1530.9766(1)1531.5882
1532.2063
1532.8307(1)1533.4617(1)1534.0991
1534.7429
1535.3932
1536.0498
1536.7130
1537.3826
1538.0587
1538.7413
1539.4304(1)1540.1259(1)1540.8280(1)Length:Width
HeightMounting holes

50mm
13.9mm
11.1mm2 holes, 25.4mm on centers, threaded4-40 (standard) or 3.5mm (option)

Length:Diameter
Tipoff length

30 mm
5 mm OD<5 mmTube

Ordering Information for Instrument housing:
The cells may be ordered enclosed in a metal instrument housing for protection
against fiber breakage and for convenience in laboratory applications. Up to twocells of any type (ie hydrogen cyanide, carbon monoxide, etc) can be ordered in agiven housing. The housing used is 28 cm wide by 6.5 cm high by 32 cm deep. Toorder this option append “with instrument housing” to part number.

200 Torr Acetylene LinesAcetylene absorption vacuum center wavelengths of the ν1+ν3 band of 12C2H2.
Wavelengths are adjusted for the pressure shift of 200 Torr. The US National
Institute of Standards and Technology (NIST) has measured these lines on asimilar cell of their own design. Not all lines were directly measured for pressureshift. Lines not directly measured were fit to the pattern of pressure shift values asa function of line number from the very accurate low pressure values. The
additional errors associated with this procedure are estimated to be <0.1pm. Thelines directly measured are indicated by (1) after the wavelength. These lines areknown with an expanded uncertainty of 0.1pm coverage factor 2. The coveragefactor 2 means the 1 uncertainty is 0.05pm. The uncertainty in the other lines is
estimated to be <0.3pm 1 .
− 0.872025Transmission (dB)2

Data i2

123

1

4R branch

P branch96− 6.472

81510

1515

1.511 ×10

31520

1525

1530

1535

1540

Ref i ,(nm)0Wavelength

Plot of transmission of M style 200 Torr acetylene cell taken on OSA with 10 pm resolution

1545
1.543 ×103