Industrial lasers are high power pieces of equipment that occasionally function under undesirable operating conditions. For example, the performance of a transverse-flow DC-excited gas laser can be adversely affected by many factors such as electrode arcing, poor lens and mirror cleanliness, focusing problems, improper gas mixture composition, poor gas quality, poor beam stability, poor beam path cleanliness, operator error, poor maintenance, poor chiller water temperature and flow rate stability, and improper laser beam ramp-in/ramp-out rates. Many of these factors which occur in the production environment are unpredictable and therefore difficult to simulate in the laboratory or the laser manufacturer’s facilities.

In this paper, a power distribution model of a transverse flow DC-excited CO2 laser is developed and validated to link the input discharge power to the output laser beam power, as well as, the heat losses. This model establishes a foundation for monitoring the laser performance by measuring signals critical to the laser performance such as temperature, pressure, voltage, current, and gas mixture flow rate and quality. The results show that quantitative thresholds can be defined based on the proposed model to detect some impending system faults for preventive maintenance purposes.

1.
Pedrotti
,
F.L.
and
Pedrotti
,
L.S.
Introduction to Optics
.
Englewood Cliffs, NJ
:
Prentice Hall
,
1993
.
2.
Li
,
L
,
Hibberd
,
R.H.
, and
Steen
W.M.
In-process laser power monitoring and feedback control
.
Proc. 4th Int. Conf. Lasers in Manufacturing
,
Birmingham, UK
,
12
14
May
1987
, pp.
165
175
.
3.
Rofin-Sinar 850I Manual
.
Rofin-Sinar Inc
., Revision B, June
1991
.
4.
Manual for Rofin-Sinar Lasers
.
Rofin-Sinar Inc
., Revision C, April
1993
.
5.
Denes
,
L.J.
and
Lowke
,
J.J.
V-I
Characteristics of Pulsed CO2 Laser Discharges
.
Appl. Phys. Lett
.,
23
:
3
,
130
132
,
1973
.
6.
Lowke
,
J.J.
,
Phelps
,
A.V.
, and
Irwin
,
B.W.
Predicted electron transport coefficients and operating characteristics of CO2-N2-He laser mixtures
.
J. Appl. Phys
.,
44
:
10
,
4664
4670
,
1973
.
7.
Cherrington
,
B.E.
Gaseous Electronics and Gas Lasers
.
New York
:
Pergamon Press
,
1979
.
8.
Verdeyen
,
T.J.
,
Laser Electronics
,
Englewood Cliffs, NJ
:
Prentice-Hall, Englewood Cliffs
,
1993
.
9.
Hecht
,
J.
The Laser Guidebook
New York
:
McGraw-Hill
,
1992
.
10.
Incropera
,
F.P.
and
DeWitt
,
D.P.
Introduction to Heat Transfer
.
New York
:
John Wiley & Sons
,
1985
.
11.
Basanese
,
R.E.
Water Flow Measurement Test 850E
.
Rofin-Sinar Inc.
,
1991
.
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