3B Scientific Helium-Neon Laser User Manual

3B SCIENTIFIC® PHYSICS

He-Ne laser U21840

Instruction sheet

01/07 Alf

1. Safety instructions

The He-Ne laser, U21840, emits visible radiation at
a wavelength of 630-680 nm with a maximum
power of less than 1 mW, thus conforming to class
2 regulations as specified in DIN EN 60825-1 “Safety
of lasers”, i.e. the human eye can be protected by
the instinctive reaction to turn away and blink.

• Do not look straight into the laser beam or any

reflected beam.

• Lasers should only be operated by trained and

authorised personnel.

• All those people participating in or observing

an experiment must have been informed of the
dangers inherent in laser radiation and edu­cated regarding protective measures.

• Experiments may only be performed using the

minimum power output required in each spe­cific instance.

• Ensure that the beam is not directed at eye

level.

• Use suitable screening to isolate the area

around the laser and avoid unwanted reflec­tions.

• Observe the regulations valid in the respective

• Keys should be carefully stored so that they

Safe operation of the He-Ne laser is guaranteed,
provided it is used correctly. However, there is no
guarantee of safety if the equipment is used in an
inappropriate or careless manner. If it is deemed
that the equipment can no longer be operated
without risk (e.g. visible damage has occurred), the
laser should be switched off immediately and se­cured against any unintended use.

• Before putting the equipment into operation,

• Due to internal operating and triggering volt-

1 Plug-in power supply
2 Lever for neutral filter
3 Light outlet with thread for

microscope objective
4 Stand rod
5 Key switch
6 Indicator lamp

country where the experiment is being per­formed, e.g. Germany’s health and safety regu­lations BGV B2 “Laser radiation”, and any
stipulations set by the relevant ministry.

cannot be accessed by unauthorised persons.

check for any signs of damage. In the event of
any malfunction or visible damage, turn off the
laser and put it away so that it cannot be used
unintentionally.

ages which can be hazardous to life, never
open the housing.

• Any rooms in which laser experiments take

place should be labelled with warning signs.

1

2. Description

The He-Ne laser is a coherent, monochromatic light
source for experiments on reflection, refraction,
diffraction and interference, for the creation and
display of holograms, as well as for rotating the
plane of polarisation (saccharimetry, Kerr effect,
Faraday effect).

The He-Ne-Laser has an anodised metal housing
with a key switch and a neutral filter for attenuat­ing the beam. Power is supplied via a plug-in
power supply unit. To disperse the beam, micro­scope objectives may be screwed onto the light
outlet.

2.1 Scope of delivery

1 He-Ne laser
2 Key
2 Stand rods (long and short)
1 Plug-in power supply

2.2 Accessories

For beam dispersal:
e.g. achromatic objective 4x / 0.10 W30613

4. Operation

• Plug the power supply for the laser into the

mains.

• Turn the key 90° to the right to switch on the

laser.

A laser beam may emerge immediately or after a
few seconds (if the equipment has not been used
for some time). An indicator lamp lights when the
laser is switched on.

• To turn off the laser turn the key 90° to the

left.

• To select the power of the laser, the filter lever

may be set to the required position so that the
neutral filter is swung in or out of the beam.

• For dispersal of the beam, screw a microscope

objective onto the thread.

3. Technical data

Output power: < 0.2 mW, max. 1 mW

(without filter), class 2
Wavelength: 633 nm
Beam diameter: 0.48 mm
Beam dispersal: 1.7 mrad
Mode: TEMoo
Polarisation: Random
Lifespan: > 12000 hours
Power supply: 12 V DC, 1 A
Dimensions: 200 x 40 x 50 mm
Weight: 0.6 kg approx.

3B Scientific GmbH • Rudorffweg 8 • 21031 Hamburg • Germany • www.3bscientific.com

Subject to technical amendments.