The NEW UPDATED NRT-150 with dual outputs


The NRT-150 Log Detector is a useful photodiode amplifier designed to measure low light levels, below - 90 dBm.

July 26, 2016


We initially developed the NRT-150 to help customers using the NRT-2500 or NRT-250 for Tracker applications, specifically when trying to track to a minimum light level. This problem is challenging. On one hand the goal is to minimize the number of photons, yet you need photons to generate a reliable Tracker feedback signal. With a (normal) linear photodiode amplifier, the voltage gets too small to track as minimization darkens the output. Using the NRT-150 log amplifier ‘compresses’ the high power voltage output and ‘expands’ the voltage output at lower optical power.

We have redesigned the NRT-150 to take advantage of newer log amplifier designs with more dynamic range and much faster response. Below is an example of the new NRT-150 log detector, over 9 decades of detected optical power, from both analog outputs.

Greater than 90 dB dynamic range over 4 V

Key Specifications

  1. Calibrated from < -90 dBm to >0 dBm.
  2. Response greater than 4 MHz
  3. Dual buffered analog (BNC) voltage outputs
  4. Compact size

User Manual

Surprise! There is no user manual. Here is all you need to operate the NRT-150 log detector.

  1. Plug in the NRT-150 to the DC power supply.
  2. Turn it on.
  3. Connect the optical power.
  4. Read/output analog voltages from the BNCs as feedback for NRT Acquirer or NRT Tracker. Or monitor on a digital voltmeter or oscilloscope, etc.

The conversion of optical power to voltage is supplied with each unit, calibrated from above 0 dBm to below -90 dBm. The approximate conversion is Vout = 0.039 Ă— Optical Power [dBm] + 3.581 , a fit to the representative data from the table below.

Optical Power [dBm]Voltage [example]

If you need more information or have other questions, please contact us at New Ridge Technologies:

[email protected] or call: +1-410-753-3055