conoptics 302RM User manual

[DOCUMENT SUBTITLE]
Model 302RM Manual

1
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Overiview:
The Model 302RM is a Linear, high voltage, differential amplifier designed to drive a
capacitive load such as Conoptics 350, 360, 370 series E.O. modulators. The amplifier
is DC coupled and is capable of putting out a maximum of 750 volts peak-to-peak. The
input of the amplifier will accept either bipolar or unipolar signal formats and has a
switchable input impedance of either 50 ohms or 1K ohm. The maximum input level
requirement is 2V P-P for full output.
Caution Before Appying Power:
Please review this manual and become familiar with all safety markings and instructions.
Insure that the equipment mains (line) voltage as specified on the rear panel is in
accordance with desired AC source. Safe operation of this equipment may be
jeopardized by use other than specified by Conoptics.
Intended Use:
This equipment is designed for general laboratory use. It is intended to be used with a
number of Conoptics Electro-Optic Modulators only. The amplifier is designed to drive a
capacitive load that is floating with respect to ground. Any use other than in direct
connection with supplied optical modulator can result in severe damage to the amplifier
and potentially hazardous voltages to external equipment and personnel. This amplifier
must only be used in accordance with the detailed instructions provided in the manual.
Warning: Hazardous Voltage:
Hazardous AC and DC voltages are present on the center pins of the BNC connectors on
the rear panel marked J1 and J2 “AMPLIFIER OUTPUT”. No attempt should be made to
come into contact with these pins or to attempt to verify operation of the amplifier by
monitoring these connectors with an oscilloscope or other test equipment. In addition, the
equipment should be turned off before any of the supplied cables are connected to or
disconnected from the driver or modulator.

2
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Safety Ground:
This equipment is equipped with a protective earth terminal. This terminal is provided by a
common or ground wire in the power cord. The main power source must supply an
uninterrupted return to an earth ground. The equipment must not be used if this earth
return is not supplied.
Service Caution:
Only qualified personnel must perform adjustment, maintenance, or repair of the
equipment. Hazardous voltages are present within the instrument and contact mresult in
personal injury. Any attempt to trouble shoot or adjust any controls within the system
should be discussed with Conoptics first at [email protected]m.

3
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
M302RM SYSTEM SPECIFICATIONS:
Cabinet
Driver and power supply in single cabinet
Test Feature
Built-in test feature allows testing for max transmission of Pockel
Cell without adjusting bias voltage
Input Impedance
Choice of amplifier input impedance by rear panel switch
(50ohm/1K ohm)
DC Bias Range
+/- 450VDC controlled by ten-turn front panel pot. Digital meter
monitors differential bias applied to E.O. Modulator
Linearity
10bits referenced to full scale (.1%)
Main Input
System is configured for country use. May be wired for 100,
120, 230/240. 50/60Hz. Refer to label on rear panel of power
supply for correct AC input
Bandwidth
DC to >200Khz with 90pf load and 3M (RG-62) cables
Max. Output Drive
Level
750VP-P into 90pf load
Amplifier Input
Signal
2VP-P max into 50/1K ohms delivers 750VP-P out
Input Signal Format
Options include Unipolar positive, negative or bipolar
Input Power (AC)
60W typical. Input power is both load (modulator) and
frequency dependent.
Dimensions
19” Rack Mountable, 5.25”H(133mm) (3U) x 14”D (356mm)
Cooling
Forced air
Operating
Environment
Designed for laboratory use (indoor only)
Temperature range +5deg C to +50deg C ambient
Humidity 20%-80% RH up to 32deg C, Altitude <3000M
Weight
20lbs (9.07kg)

4
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
OPERATING INSTRUCTIONS:
The Model 302RM amplifier is designed to drive a number of different Conoptics E.O.
modulators. All types of modulators supplied with the system are configured as lumped
capacitors (two terminal devices). The amplifier has a 50/1K ohm, single ended input (J3
SIGNAL INPUT) and a push/pull output (J1 & J2). The amplifier has a forward gain of
approximately 375V/V push pull. Maximum output is 750V p-p. The amplifier is a linear,
high voltage design for use as an optical shutter, phase modulator, or polarization rotator.
It will accept a variety of different input signals and amplify them linearly within the
bandwidth limitations of the amplifier. A variable DC bias voltage is summed into the
output connectors (J1 & J2) to allow the operator to set the quiescent operating point of
the optical modulator. This bias voltage is adjustable via a ten-turn potentiometer on the
front panel. The digital meter on the front panel indicates the true dc differential bias
voltage across the modulator terminals.

5
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Figure 1
In Figure 1 above, the scope trace straight-line signal is the input waveform (triangular
wave) to the driver. The sinusoidal waveform (sine squared) is the detected response to
the linear input ramp. The DC bias voltage allows the operator to essentially “slide” the
detected signal along the x-axis to allow the initial condition (0 volts in “equals” 0 light out)
to be set correctly. The modulators static transmission (no voltage applied to modulator)
may vary due to ambient temperature, throughput laser power etc. The bias voltage is
employed to allow the user to compensate for these effects.
Because the system is DC coupled, provisions must be made in the drive electronics to
accommodate various types of input signals. Naturally, any DC offset in the input
waveform will be amplified to the same degree as the signal itself. To allow the driver to
accept either bipolar or unipolar input signals, a DC offset is applied internally to the
amplifier to maximize the useful dynamic range of the amplifier. This offset is controlled by
two separate slide switches on the rear panel of the cabinet. The switch is marked
BIPOLAR, UNIPOLAR +, UNIPOLAR -.

6
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Bipolar: This format is used for input signals that extend both above and below ground
by an equal amount.
Typical Bipolar Input

7
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Unipolar Positive:
Unipolar positive: This is the most commonly used type of input signal. Typically the signal
comes from a pulse generator, D-A converter or function generator. This signal goes from
0v to some positive value of less than 2v peak.
Typical Unipolar Positive Input

8
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Unipolar Negative:
This input format is not used that often, but it is included in the event that it is required.
Typically, this format is obtained from a D-A converter.
Typical Unipolar Negative Input

9
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
If the switches on the rear panel of the cabinet are not in the correct position for the desired
input waveform, the input signal will drive the amplifier into saturation and cutoff. This
action will severely distort the drive signal going to the modulator. The position of this
switch should be set to the correct position before power is applied to the system. Since
this amplifier is capable of outputting 750vp-p, it can easily overdrive the modulator at
shorter wavelengths. Please check what the modulators “half wave” voltage is before
applying an input signal to the driver. The forward gain of the amplifier is approximately
375v/v. The correct input level of the input signal can be determined by knowing both the
amplifier gain and “half wave” voltage of the modulator at the desired operating wavelength.
Below is an example of the 1/2 wave voltage requirements for KD*P& LTA series
modulators.
Model
Number
V ½
wave @
500nm
V ½
wave
@
830nm
V ½
wave
@1064nm
V ½
wave
@2500nm
Aperture
Diameter
Resonances
Contrast Ration
@ 633nm and
1064nm
Length
w/
Polarizer
KD*P Crystal
Series
Wavelength
Limits (240
to 1100nm)*
M350-50
455
757
970
--
3.1mm
Yes **
500:1, 700:1
106mm
M350-80
261
433
522
--
2.7mm
Yes
500:1, 700:1
137mm
M350-
80LA
360
600
720
--
3.5mm
Yes
500:1, 700:1
137mm
M350-
105
226
376
472
--
3.1mm
Yes
500:1, 700:1
162mm
LTA Crystal
Series
Wavelength
Limits
(700 to
2000nm)
M360-40
--
312
400
950
2.7mm
Yes
N/A, 200:1
95mm
M360-80
--
143
183
430
2.7mm
Yes
N/A, 100:1
137mm

10
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Input Signal Selection Switches:
Input Impedance Select Switch: Sets the input impedance of the amplifier, typically 50ohms
when input signal is from a pulse generator or function generator.
Input Format Switch: Sets the amplifier correctly to receive the desired input signal as
described in the previous section
Unipolar +/- Switch: Sets the amplifier to receive either a positive or negative going unipolar
type input signal.
Input
Impedance
Select Switch
Input Signal
Switch
Unipolar
+/- Switch

11
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Driver Self-Test Function
-The self-test inset on the front panel of the M302RM is designed to allow the user to check
the operation of both the drive electronics and the optical head in one step. DC voltage that
is user adjustable is injected into the front end of the drive electronics when the “Push to
Test” button is momentarily depressed. This voltage is adjustable from 0 volts to + 2.0V
which is sufficient to drive the amplifier to the rails of the power supply. The unit must be run
in the unipolar positive input signal mode to operate this function.
Typical setup is as follows.
1. Remove any input signal connected to J3 on the rear panel. ( this will not have to be
done again after the proper test voltage is set)
2. Monitor both test pins with a DVM set to DC volts.
3. Adjust the trim potentiometer above the test points with a small screw driver to
obtain the required DC voltage which is: [half wave voltage of the modulator at the
operating laser wavelength] divided by 375.

12
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Optional - 302rm Driver Bias Control Switch
Switch Positions:
1. Front Panel: Allows the operator to control the optical bias of the modulator from the
front panel potentiometer.
2. External: Allows the operator to supply a remotely derived DC Voltage to the bias
control electronics to operate the bias on the E.O. Modulator
a. Range: +/- 10V at input drives bias voltage on cell +/- 430VDC
b. Input Impedance: Approx. 100K resistive
c. Bandwidth: Designed for DC input only. Do Not Attempt to operate over 5Hz

13
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Placement of PUH-Pins for Various Ac Line Voltages
302RM Line Voltage Set at
100VAC
Connect: D-C, F-E, I-J
302RM Line Voltage Set at
230VAC
Connect: B-A, F-G

14
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
302RM Line Voltage Set at
115VAC
Connect: B-A, F-E, G-H

15
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
Cable Connection (Model 302RM to E.O. Modulator)
This section describes how to properly connect our E.O Modulators that use BNC
connectors to our Model 302RM amplifier that uses MHV connectors.
Key: Amplifier MHV Connectors- Cable ends are labeled P1 and P2
E.O Modulator BNC Connectors- Cable Ends are labeled P1M and P2M
***Please don’t reverse the connectors***

16
Conoptics Inc. 19 Eagle Rd. Danbury, CT 06810 Phone [phone] Fax [phone]
Email: [email protected] , or visit www.conoptics.com
The rear panel of the Model 302RM amplifier uses MHV Connectors. The cables are
labeled P1 and P2. The picture below identifies the proper connection to the amplifier
The rear panel of the Model 302RM amplifier uses MHV Connectors. The cables are
labeled P1 and P2. The picture below identifies the proper connection to the amplifier