Arroyo Instruments LaserMount 234B User manual

Page 2 · 234B Series TEC TO-Can LaserMount User’s Manual
Table of Contents
Introduction ...............................................................................................3
Installation and Use...................................................................................4
Configuring the Temperature Controller.................................................10
Working with Thermistors .......................................................................10
TEC Lifetime............................................................................................12
Connector Pin-Outs ................................................................................13
Technical Specifications .........................................................................14
Thermal Capacity ....................................................................................15
Mechanical Specifications ......................................................................16
Laser Diode Protection............................................................................22
Warranty..................................................................................................23
Service and Support ...............................................................................23

234B Series TEC TO-Can LaserMount User’s Manual · Page 3
Introduction
Thank you for choosing the 234B TEC TO-Can LaserMount from Arroyo
Instruments. The 234B LaserMount is designed for high performance and long
term use.
The 234B LaserMount is a higher performance TO-can mount, similar to our
smaller 224 LaserMount, but offering a much higher thermal capacity (up to
10W at 25°C), lower operating temperatures, and a much higher 3A higher laser
current capacity. The 234B integrates dual Peltier coolers for precise control of
the package temperature. With an operating range of -5°C to +85°C, the 234B
LaserMount covers a wide range of temperature control needs.
The 234B has a cover plate with a small opening whose face is close to the
diode as well as mounting holes for 30mm CAGE systems. For applications
using 1” lens tubes, there is an optional 234-C-02 cover plate, which replaces
the small opening with a larger, 1” threaded opening compatible with 1” lens
tube systems.
When coupled with the 234-OFFSET-KIT, the 234B can be used with 2-pin 1mm
offset mounted lasers from manufacturers such as the Nichia, Mitsubishi, and
others.
The mount requires no wiring thanks to a simple configuration switches
conveniently located on the rear of the fixture. 234B LaserMount is also finned
to provide the highest heat dissipation capability, and is designed to be posted
mounted (post mount not included).
The 234B LaserMount also offers all the features you would expect from a
modern TO-Can laser diode fixture, including:
•Designed to be quickly integrated with Arroyo’s LaserSource and
TECSource instruments.
•Industry-standard D-sub connectors and pin-outs allow for quick
integration into existing laser applications.
•Banana plug for case ground, which can be used as a wrist strap
connection or to assure proper grounding to an optical table or test
bench.
Note: photos in this manual may show a CAGE system or post mount. The 234B does not
come with either of these systems; they are shown for illustrative purposes only.

Page 4 · 234B Series TEC TO-Can LaserMount User’s Manual
Installation and Use
Configuring the mount: Start by identifying the specific electrical configuration
style of your device from the illustrations below. The switch settings for each
style are illustrated on the following page. For two pin devices (style G), which
have their pins at the 3 o’clock and 9 o’clock positions, the third switch must be
placed in the N/C position.
Style A Style B Style C Style D Style E Style G Style H
Laser Styles
The upper and lower holes of the laser socket, labeled the COM pins, are always
tied together. The PD and LD switches on either side of socket are to set the
polarity of the outside pin. For example, if your device has the laser cathode
common to the photodiode anode (lower left diagram above), when you plug in
your device, the left hole would have the photodiode cathode (except for style G
lasers, in which case, the left hole is laser cathode), and the right hole would
have the laser anode.
When installing your laser, the isolated (non-common) photodiode pin goes into
the left (PD/LD) hole of the laser socket, and the isolated (non-common) laser
pin goes into the right (LD) hole of the laser socket. The common pin can go into
either the upper or lower hole.
For style G 2-pin packages, the laser anode pin should go into the right (LD)
hole of the socket while the laser cathode pin goes into the left (PD/LD) hole of
the socket.
If you have a 4-pin TO-can package where the laser and photodiode are
completely isolated from each other, the mount will connect the two pins that are
inserted into the COM positions of the socket. For example, consider the
following 4-pin laser configuration:
When inserted into the fixture as shown, the laser anode and photodiode
cathode pins will be connected together, making the laser equivalent to style A,
and the switches should be set accordingly.
Installed
➔

234B Series TEC TO-Can LaserMount User’s Manual · Page 5
LD
LDAPDA
N/C
PD
LD PDCLDC
PD/LD
LD
COM
PD /
LD
LD
LDAPDA
N/C
PD
LD PDCLDC
PD/LD
LD
COM
PD /
LD
LD
LDAPDA
N/C
PD
LD PDCLDC
PD/LD
LD
COM
PD /
LD
LD
LDAPDA
N/C
PD
LD PDCLDC
PD/LD
LD
COM
PD /
LD
LD Anode and PD Cathode Common
Style A (or E)
Common Cathode
Style B (or H)
LD Cathode & PD Anode Common
Style C
Common Anode
Style D
2-Pin Laser
Style G
LD
LDAPDA
N/C
PD
LD PDCLDC
PD/LD
LD
PD /
LD
» Note the middle (N/C) position of the third switch «

Page 6 · 234B Series TEC TO-Can LaserMount User’s Manual
Face of 234B with cover off
Connect to Laser Diode Driver and TEC Controller: Next, connect the 234B to
your laser diode driver and temperature controller.
NOTE
Arroyo Instruments offers Laser and TEC cables designed to connect
directly between our LaserSource and TECSource products. If you
use your own cables, ensure the connections are properly made
between the instrument and the mount, and that proper grounding
techniques are used. The pin-out of the connectors can be found later
in this document.
WARNING
Be sure you are properly ESD protected before handling your laser. For
additional information, read the section titled “Laser Diode Protection”
later in this manual.

234B Series TEC TO-Can LaserMount User’s Manual · Page 7
Mounting your device: Insert the device so that the common pin is the top or
bottom pin, the isolated photodiode pin is on the left, and the isolated laser pin
is on the right. If using a 2-pin style G laser, the laser anode would be to the right
and the laser cathode to the left. The illustrations below show the mounting of a
free-space TO-can laser, but the fiber-pigtailed device would mount in a similar
fashion.
Your pin length must be in the range of 5mm to 9mm; most diodes are 6.25mm.
Longer pins must be trimmed or they will bend when clamping the diode.
No Laser Laser Loose
Once the device is loaded, for free-space TO-can lasers, use the provided
5.6mm or 9mm diode clip to clamp the TO-can to the temperature-controlled
gold plate. For fiber pigtailed lasers, the panel mount holes will line up with
either the inside (for 5.6mm) or outside (for 9mm) holes, or the top and bottom
holes when mounting vertically housed packages, such as those available from
Thorlabs.
Clip, 1 Screw Clip, 2 Screws

Page 8 · 234B Series TEC TO-Can LaserMount User’s Manual
When tightening the screws, do not over tighten, which may strip the threads.
Do not tighten one side more than the other, as poor or uneven temperature
control may result; the two pictures below show a correct and improper use of
the diode clip:
GOOD: Diode properly clamped, BAD: Diode improperly clamped,
clip is even with cold plate clip is uneven with cold plate
The photos below illustrate the various covers and clips:
Standard cover plate Optional 234-C-02 cover plate
1mm offset cover plate

234B Series TEC TO-Can LaserMount User’s Manual · Page 9
You may choose to install the cover. The cover is not required, but will improve
the temperature stability of the mount.
Depending on the type of the device, choose the appropriate clip to mount it:
TO-5.6 and TO-9 clips TO-9 1mm offset clip
234B with diode loaded, 234B with diode loaded,
standard cover optional 234-C-02 cover
234B with CAGE system attached
(CAGE system not included)

Page 10 · 234B Series TEC TO-Can LaserMount User’s Manual
Configuring the Temperature Controller
The Arroyo Instruments 5305 TECSource or 5240 TECSource are the
recommended temperature controllers for this mount. When using an Arroyo
Instruments temperature controller, the easiest method for configuring the
controller to operate with the mount is to change the Mount setting in the menu
to 234B. This will change the sensor settings, current limit, and fan settings to be
appropriate for this mount. If you have an older Arroyo Instruments temperature
controller that does not have this selection, there may be an upgrade available
for your instrument, check with the factory for more information, or simply adjust
the current limit to no more than the maximum current of the 234B.
If you will be using a non-Arroyo controller, make sure to adjust the limits and
sensor settings appropriately to ensure proper and safe operation of the mount.
Working with Thermistors
The 234B is equipped with a 10kΩ negative temperature coefficient (NTC)
thermistor, specifically, the BetaTHERM 10K3A1. A thermistor works by
translating temperature into resistance, with resistance decreasing as
temperature increases (hence the ‘negative coefficient’).
Below is the response curve of the thermistor:
0
10,000
20,000
30,000
40,000
50,000
-10 010 20 30 40 50 60 70 80 90 100
Resistance (Ω)
Temperature(°C)
Thermistor Resistance vs Temperature

234B Series TEC TO-Can LaserMount User’s Manual · Page 11
As can be seen be the graph, the resistance of the thermistor drops very quickly.
In the typical control range (0°C to 40°C), typical 10K thermistors offer good
sensitivity to changes in temperature, and this is the range in which most 10K
thermistors are typically used. 10K thermistors can be used at much higher
temperatures, but will suffer poorer temperature stability performance because
of the lower sensitivity.
All Arroyo temperature controllers support operation using a 10μA or 100μA
thermistor bias, which limits the upper control range to 450kΩ or 45kΩ,
respectively. To minimize noise and maximize stability, you should select
highest current while still allowing you full operation across your required
temperature range. The typical setting is 100μA, but your application will
determine the actual needs.
The Steinhart-Hart Equation
As can be seen from the temperature versus resistance graph above, resistance
varies inversely with temperature in a non-linear fashion. This relationship can be
accurately modeled by polynomial equations, and one such being the Steinhart-
Hart equation:
3
)ln(*)ln(*
1RCRBA
T++=
The coefficients for the BetaTHERM 10K3A1 thermistor are:
A = 1.12924x10-3
B = 2.34108x10-4
C = 0.87755x10-7
These are the default coefficients for Arroyo Instruments temperature controllers,
but can be changed in the Sensor menu, or by selecting the appropriate 234B
mount from the Mount menu setting.

Page 12 · 234B Series TEC TO-Can LaserMount User’s Manual
TEC Lifetime
While the TEC elements in the 234B are semiconductor devices, they do wear
over time. The life of a TEC module is based on several parameters, but three
parameters in particular will affect the lifetime performance of the TEC:
1. The most damaging operation for a TEC is continuous thermal cycling,
particularly when the high temperature is near the upper operating
range of the TEC and/or where the TEC is operated near its current
limits. In these applications, anticipate a much shorter lifetime for the
TEC.
2. Operating the TEC for prolonged periods at or near the maximum
current or temperature. While not as harsh as thermal cycling, high
operating temperatures will still degrade the TEC more quickly.
3. Mechanical stresses caused by uneven surfaces, uneven compression,
or sheer or uneven loads. Arroyo Instruments mounts are designed to
avoid these conditions, but can still be induced by customer loads in
the final application.
The first two issues can be mitigated (lessened) by operating the TEC below its
current limit. While the 234B has a maximum operating current of 5.6A, we
recommend operating the mount at no more than 75% of the rated current
(approximately 4.3A).
The application will dictate the thermal cycling and temperature requirements,
but understand that operating under more extreme conditions simply means the
TECs in the 234B may need to be replaced more frequently.
In predicting lifetimes, under normal operating conditions (operating at 50% load
or less around 25°C), which is the most common application, the TECs should
last for years. Under very harsh operating conditions, TECs could wear out in as
short as 4 to 6 months, possibly even less. If you have a question on how best to
operate your mount under harsh conditions, contact the factory for additional
support.

234B Series TEC TO-Can LaserMount User’s Manual · Page 13
Connector Pin-Outs
234B Rear Connectors
DB-9 Pin
Description
1 –3
No connection
4 & 5
Laser cathode
6
Photodiode cathode
7
Photodiode anode
8 & 9
Laser anode
Laser DB-9 Connector Pin-Out
DB-15 Pin
Description
1 & 2
TE (+)
3 & 4
TE (-)
7
Thermistor
8
Thermistor
11
FAN (+)
12
FAN (–)
5, 6, 9-15
No connection
TEC DB-15 Connector Pin-Out
The nitrogen fitting is intended for use with lid-less TO-can applications, or
where condensation might occur. The recommended flow rate is 2-3 CFH, or
whatever is required to prevent condensation.

Page 14 · 234B Series TEC TO-Can LaserMount User’s Manual
Technical Specifications
FICATIONS
234B TEC TO-Can LaserMount
Laser
Packages Supported
5.6mm and 9mm TO-Can, 2, 3 & 4
pin. 2-pin 1mm offset packages with
optional 234-OFFSET-KIT.
Fiber Pigtailed Package Support
Flange mount, 12mm or 18mm
horizontal hole spacing, or 0.75”
(19.1mm) vertical hole spacing.
Pin Length Range
5mm to 9mm
Maximum Laser Current
3 Amps
Temperature Control
Temperature Range
-5°C to +85°C
Sensor Type
10kΩ Thermistor
TE Module (at 25°C)
Imax = 5.6A
Vmax =7.2V
Recommended Controller
5305 or 5240 TECSource
Mechanical Summary
Maximum Thread Depth
[in(mm)]
0.15” [3.8mm]
Center hole
0.27” [6.9mm], straight through
Cage mount
4-40 x 4 holes, 30mm on center
Size (H x W x D) [in(mm)]
3.0 (76.2) x 3.0 (76.2) x 2.91 (73.9)
234B with 234-C-02 Cover Plate
Center hole
1.035”-40, threaded through
Cage mount
4-40 x 4 holes, 30mm on center
Size (H x W x D) [in(mm)]
3.0 (76.2) x 3.0 (76.2) x 3.19 (80.9)
Connectors
Laser Diode
DB-9, male
Mount TEC
DB-15, male
Nitrogen
1/16” barb
Case Ground
4mm banana jack
General
Fan Power
12VDC, 210mA max
Mounting holes
8-32 and M4 threaded holes

234B Series TEC TO-Can LaserMount User’s Manual · Page 15
Thermal Capacity
The maximum thermal load supported by the 234B depends on the ambient
temperature and cold plate temperature, as shown by the graph below.
The performance is based on an ambient temperature of 25°C, and actual
performance will be improved or degraded if the ambient temperature is lower or
higher, respectively.
0.0
5.0
10.0
15.0
20.0
25.0
-10 010 20 30 40 50 60 70
Maximum ThermalLoad (W)
Plate Temperature (°C)
234 Thermal Capacity
(25°C Ambient)
When operating at temperatures that cause condensation (below the dew point),
the fixture must be purged with nitrogen to prevent the condensation of moisture
for two reasons:
1. The energy required to condense the moisture from the air will
significantly degrade the performance of the fixture; and
2. Condensation can lead to an accumulation of water inside the fixture,
which, over time, can cause corrosion and interfere with the proper
operation of the mount.

Page 16 · 234B Series TEC TO-Can LaserMount User’s Manual
v
Mechanical Specifications
Front Detail View

234B Series TEC TO-Can LaserMount User’s Manual · Page 17
TO-5.6 Clip
TO-9 Clip

Page 18 · 234B Series TEC TO-Can LaserMount User’s Manual
TO-9 1mm Offset Clip
234B with Standard Cover, Front View

234B Series TEC TO-Can LaserMount User’s Manual · Page 19
234B with 1mm Offset Cover, Front View
234B with Standard or 1mm Offset Covers, Side View

Page 20 · 234B Series TEC TO-Can LaserMount User’s Manual
234B with 234-C-02 Cover, Front View
234B with 234-C-02 Cover, Side View