Local rules document - University of Cambridge

Local Rules

for the safe use of the
supercontinuum

laser system


Location: Chemical Engineering, Pembroke Street
,

Room:
L
aser Suite

(lab D)
, Basement


Responsible person:

Rosalynne Watt


Department of Chemical Engineering


University of Cambridge


New Muse
ums Site, Pembroke St.


CB2 3RA, UK


Tel: +44 (0)1223 330133


Fax: +44 (0)1223 334796


Email: rsw32@cam.ac.uk


Laser Safety Officer:

Dr.
Johan Hult


Department of Chemical Engineering


University of Cambridge


New Museums Site, Pembroke St.


CB2 3RA, UK


T
el: +44 (0)1223 334777


Fax: +44 (0)1223 334796


Email: jfh36@cam.ac.uk


Laser protection advi
ser:

Lisabeth Yates


The University Health and Safety Division


16 Mill Lane


Tel. ext: 66354 or 33301


Email: ly215@admin.cam.ac.uk


Issued under the authority o
f:


Dr.
Johan Hult


Laser Safety officer, Dept. of Chemical Engineering


1
5

May 20
0
7


Scope

These local rules cover the use of the
fiber laser and supercontinuum generation

system
located in
the Laser Suite
. They cover the

normal use and
user
maintenance
operation
s only
.
They implement the

University’s laser safety policy at a practical level and form part of the
University’s duties

under Section 2(3) of the Health and Safety at Work etc Act 1974.


Description

Mode
-
locked Ytterbium Fiber L
aser

Maximum outp
ut power:

900

m
W

Wavelength:

1065

nm

Pulse length:


5
ps

Repetition rate:


0.3
-
20

MHz

Class:

4


The fiber

laser is used to generate a supercontinuum by launc
hing the laser beam into a fiber
.
The resulting beam consis
ts of wavelengths between 800
-
17
00 nm

and has a
n average
output

power
of
less than 300 mW

(class 3 B)
.
The

supercontinuum

beam is
then
launched
into a dispersive fibre module, after which the
beam will consist of wavelengths between

1300
-
1700 nm, with
a
n

average output
power

of
less than
1

mW.

Th
is
beam is
then launched
into free space and
employed for absorption measurements.



Authoris
ation and Training

Only persons who
are adequately trained (Class 3B and 4 Laser Users Course, and In
-
lab
Training as outlined below) and authorized as listed i
n the appendix to these local rules may
work with the laser.


Main points of in
-
lab training:



1.

Familiarisation

with laser and supercontinuum sensor

operating procedures



Laser start
-
up and shut
-
down



Changing
and monitoring of
repetition rate and output power



Fibre launching



Correct handling of fibres



Collimation and alignment of supercontinuum beam



Beam termination



General good practice alignment procedures

2.

The proper use of hazard control procedures

(interlocks,
warning lights
,
laser
curtains,
Laser Suite ac
cess control system)

3.

The proper use of enclosures

4.

The need for personal protection

(type of goggles required)

5.

Accident reporting
and emergency
procedures

6.

Bioeffects of the laser upon the eye and skin


Laser Controlled Area

This laser may be operated only i
n the designated Lase
r Controlled Area.

Operation is only
allowed when the following conditions are met: Laser curtain is closed, laser warning sign is
illuminated,
t
he laser is interlocked to the Laser Suite access system,

and

the
Laser Suite
access syste
m has been switched to ‘laser on’ mode

–

which restricts access to trained and
authorized personnel only
.


Procedures

*
Before laser is switched on user must:



Activate
Laser Suite
access system

‘laser on’ mode



Illuminate laser warning light



Close laser cur
tain



Ensure that enclosures are intact



Ensure that all mounts and optical components are properly secured



Wear

designated Goggles
.


*
Start laser at lowest output power (lowest setting of
laser
power potentiometer) and ensure
that laser beam is directed in
to supercontinuum fibre, by visualizing the beam using IR
viewing card


*
Any a
lignment
(of both pump

beam into supercontinuum fibre,

and
of
supercontinuum beam

used for spectroscopic experiments
)
should be carried out using th
e lowest possible power
(cont
rolled using the

laser

power potentiometer)
.
NOTE: Laser output is
not

reduced to safe
level even at the lowest power setting
.

Laser beams should be visualized using IR viewing
card.


*
Reduce
laser
power
to minimum
before switching
laser
off


* Remove las
er key, to be kept by authorised users, inaccessible to others.


*
If in doubt on any aspect of the system an expert user must be consulted.


Protection Measures

Administrative control measures (required for all laser operation):



Restricted access (through

Laser Suite access system)



Interlocks (connected to Laser Suite access system)



Laser curtain closed



Laser warning sign illuminated


Engineering control measures (required for all laser operation):



Pump laser and fibre launch unit (class 4) to be completel
y enclosed on all sides



Coupling between supercontinuum beam and dispersive fibre (class 3B)

to be
completely enclosed



Dispersed supercontinuum beam (class 1) can safely be operated as an open beam




Personal protective equipment (required for all laser ope
ration):



CE marked protective goggles should be worn at all times.


G
oggles: CE #390806

(adequate protection against both pump and supercontinuum)


The
laser

must not be operated when feeling tired or dizzy, e.g. under the influence of alcohol
or medicatio
n.


Regular maintenance checks (at least 4 times/year) should be carried out by users and
recorded in the ‘Laser Log Book’. Those include the operation of the interlock system and
checks that the enclosures are undamaged.


Summary of Hazards

Potential seri
ous damage to eyes if local rules are not followed.

Class 4 laser system: Danger of retinal damage upon exposure.


Contingency Plan

Laser Accident: Report any laser incident or accident to your Departmental Laser Safety
Officer and your Departmental Safety

Officer who will report it to the Health and Safety
Division.

The injured person should see a specialist ophthalmologist preferably within 24
hours of the injury occurring. The injured person must not drive.

Addenbrookes has an eye
clinic where a speciali
st ophthalmologist should

be available for consultation. However, if an
ophthalmologist is not available within 24

hours of the injury occurring, you should then be
referred to the nearest specialist eye

hospital, Moorfields, which has experience in dealin
g
with laser eye injuries.


Addenbrookes Hospital


Accident and Emergency Department open 24 hours a day.


Address:
Hills Road, Cambridge CB2 2QQ UK


Telephone:
01223 245 151


Moorfields Eye Hospital


Accident and Emergency Department open 24 hours a day.


Address:
162 City Road, London EC1V 2PD


Telephone:
020 7253 3411


Other
types of
Accidents: Refer to emergency Action sheet.




Appendix

Authorised Users and User Declaration


The following users have read the local rules set out above
, the laser risk ass
essment, the
Departmental Rules for the Use of Lasers

and the university guidance on the Safe Use of
Lasers
, have attended appropriate training as set out in local rules,

and agree to work in
accordance to these rules:

Dr. Clemens Kaminski







Dr. Johan

Hult







Rosalynne Watt







Dr.
Toni Laurila








Date of next review

14

May

200
8

or when there is a significant change of equipment specification
, location

or
operating procedure.