New Focus 1480, User Manual

Page: 6 / 20

6 • Operation NEW FOCUS, Inc.
including single-mode fibers. The internal fiber is
angle polished for low back reflection.
The Model 1481 has an internal single-mode fiber,
which is angle polished to reduce back reflections. The
Model 1481-50 has an internal 50-µm multimode fiber
and uses a GRIN lens to image the fiber output onto
the 25-µm photodiode used in these models. The
optical elements are anti-reflection coated for low back
reflection at 850 nm.
Figure 1:
Models
1480 & 1481
photodetector
modules
Handling Precautions
Whenever handling the photoreceiver, make sure to
follow these precautions:
• Prior to handling the detector or making
connections, be sure to ground yourself
adequately—even small electrostatic discharges
could permanently damaged the detector. A
ground strap provides the most effective
grounding and minimizes the likelihood of
electrostatic damage.
• Do not over torque the microwave K-connector.
Excessive torque can damage connectors.
• Make sure the optical connector is clean and
undamaged before connecting it to the detector
module.
Optical Input
Off On
Batt
Chk
Bias
Monitor
FC/PC connector
for fiber optic input
Bias-monitor port—output
is equal to photodiode current
times 1000
Ω
, for 1 mV/
µ
A.
Power switch
Battery-check button—
press to apply the photo-
diode bias voltage to
the bias-monitor port.
2.00 (50.8)
2.25 (57.1)
2.00
(50.8)
Output K-connector
3.14 (79.8)
1480 FC Det revA.fm Page 6 Monday, March 13, 2000 2:55 PM