TELEDYNE
JUDSON TECHNOLOGIES
A Teledyne Technologies Company 2/7
J22 and J23 SERIES
InGaAs PHOTODIODES
Operating Instructions
Operating Circuits
The recommended circuit for most
applications is an op-amp in a
negative-feedback transimpedance
configuration (Fig. 2). The feedback
circuit converts the detector output
current to a voltage, while the op-
amp maintains the detector near
zero-volt bias for lowest noise.
An undesirable DC offset current, or
"dark current", will be produced in
this configuration. It is a function of
the preamp input bias current Ib, the
preamp input offset voltage Vos, and
the detector shunt resistance RD.
This total "dark current" is:
Total ID = Ib+ (Vos / RD)
Selection of the proper op-amp is
important for low preamp noise and
best system bandwidth. For higher
RD detectors, choose a preamp with
low bias current; for lower RD
detectors, choose a preamp with low
offset voltage.
Testing
J22 and J23 Series room temperature
InGaAs detectors are designed for
operation under ambient conditions
to +60°C.
Each device is tested for:
• Minimum responsivity at 1550nm
• Minimum shunt impedance RD
• Maximum dark current ID
Statistical data can be provided.
Absolute response vs. wavelength
from 800 to 1800 nm is available for
detectors 2mm or larger.
Device Options
Teledyne Judson’s standard InGaAs
detectors, the J22 series, offers high
reliability and performance in the
spectral range from 0.8 µm to 1.7µm.
In addition, the J23 series extended
InGaAs detectors are available in
four cutoff options at 1.9µm, 2.2µm,
2.4µm and 2.6µm. Figure 3 shows
the typical response for the J22 and
J23 series at room temperature
operation.
Package Options
The J22 and J23 series are available
in standard TO packages, TE
cooled, LN2 cooled, ceramic sub-
mounts, and bare die. We also offer
different window materials, lenses
or optical filter options.
Accessories
For a complete system, Teledyne Judson
offers low noise transimpedance
amplifier modules, heat sink/preamp
assemblies and temperature
controllers. For further details,
please visit our website.
Call us
Let our team of application
engineers assist you in selecting
the best detector design for your
application. Or visit our website for
additional information on all of
Teledyne Judson’s products.
Figure 2.
Basic Operating Circuit