http://www.jinstartech.com/

General Attributes:

Thorlabs AMP100 very good price

AMP100

Switchable Gain: 1, 10, or 100 MV/A
Bandwidth: DC - 1 kHz
Zero Adjust & Polarity Switch

• Convert Current Output of Photodiodes to Voltage
• Available with Transimpedance Up to 100 MV/A or Bandwidth Up to 100 MHz
• Input Current Noise as Low as 0.06 pA/Hz^1/2
• Adjustable Output Voltage Offset or Photodiode Bias Voltage

Features

• Convert Current Output of Photodiodes to Voltage
• Amplifiers Optimized for High Speed or High Gain
• Fixed and Switchable Gain Models
• Models with Adjustable Zero Voltage Offset or DC Bias Voltage
• AMP145 Amplifier Bandwidth Independent of Cable Length
• Compact In-Line BNC Design with 80 g Mass
  • Approx. Dimensions: 3.80" x 1.25" x 1.00" (97 mm x 32 mm x 25 mm)
• DS5 USB Power Supply and 1.5 m Long Micro-B USB Cable Included

Thorlabs' AMP Series of Transimpedance Amplifiers are designed to amplify the output signal from unmounted or mounted photodiodes. Refer to the tables below for amplifier specifications. A switch on the output end of the amplifier (see Figures 1.1 and 1.2) allows the output signal's sign to be set based on the connected photodiode's polarity (AG or CG). For all models except the AMP140 and AMP145 amplifiers, the offset caused by the dark current of a connected photodiode can be compensated for using the Zero Adjust screw (see Figure 1.1). For the AMP140 and AMP145 amplifiers (see Figure 1.2), this screw instead adjusts the DC bias voltage applied to the photodiode.

Each transimpedance amplifier has an in-line box design with two female BNC connectors and is intended to be used between two BNC cables. SMA-mounted photodiodes can be connected directly using a CA2806 cable. The devices are powered through a Micro-B USB port using the included 5 V, 2 A power supply or any other available USB port. The internal electronics of the amplifier regulate the power to the amplification circuitry, isolating the device's performance from electrical noise that may be inherent to the power source.