Features
- InGaAs PIN photodiode
- Wavelength range from 700 to 1700 nm
- Bandwidth from DC to 20 MHz
- Max. conversion gain 9.5 x 104 V/W
- Min. NEP 3.5 pW/√Hz
- Free space input (fibre coupling by means of adapter)
| Model | HCA-S-20M-IN-FST |
|---|---|
| Photodiode | 0.5 mm Ø InGaAs-PIN |
| Spectral Range | 900 - 1700 nm |
| Bandwidth (-3 dB) | DC - 20 MHz |
| Rise/Fall Time (10 - 90 %) |
18 ns |
| Transimpedance | 1 x 105 V/A |
| Max. Conversion Gain | 9.5 x 104 V/W (@ 1550 nm) |
| Min NEP (@ 10 MHz) | 3.5 pW/√Hz (@ 1550 nm) |
| Datasheet |  |
Output voltage ±1.5 V (for linear operation @ 50 Ω load). Offset adjustable by potentiometer. Output short-circuit protected. The photoreceivers with free space input come with threaded M4 and 8-32 mounting holes for use with standard mounting posts. Power supply ±15 V via 3-pin Lemo® socket. A mating connector is provided with the device. Optional power supply PS-15 available. For further information please view the datasheet or contact FEMTO.
Plugs and sockets
FEMTO amplifiers and photoreceivers are supplied with either a BNC or SMA socket as standard, depending on the model. We are happy to fit other plugs and sockets according to your requirements. In addition to BNC, SMA and type N, other types are also available on request. Simply add your request to your quotation enquiry or contact our support team.
Customised products
Do none of the products fulfil your requirements? We offer customer-specific versions of our products, e.g. adapted bandwidth, amplification or optimisation for special signal sources. OEM versions, for example for larger projects and product integrations, are also possible. Our technical support team looks forward to your enquiry. You may also find something suitable among the related products.
High sensitivity at high bandwidth
The HCA-S-20M photoreceiver combines a fast photodiode with the proven and outstanding FEMTO HCA current amplifier technology. It is available with InGaAs photodiode covering a spectral range from 900 to 1700 nm. The electrical amplifier gain is 1 x 105 V/A resulting in a maximum conversion gain of 9.5 x 104 V/W at 1550 nm. The sophisticated DC coupled multistage amplifier design allows measurements from DC to a maximum bandwidth of 20 MHz corresponding to a minimum rise time of 17.5 ns. With a noise equivalent power (NEP) as low as 3.5 pW/√Hz signals with an optical power in the micro Watt range can be detected without the need for further averaging.
Compatible with optical bench (free space) and fibre optics
The free space input (FST) is designed as a 1.035″-40 threaded flange with a screw-on coupler ring. It opens up a broad compatibility with optical accessories from various manufacturers, such as lenses, tubes, cage systems, optical adapters etc.
The free-space input can be converted into fibre connections (FC, FSMA) easily by simply screwing on the fibre adapter of the PRA series.
The relatively large-area detector facilitates optical focusing in free-space applications and ensures a high and stable degree of coupling when using the optionally available fibre optic adapter. For models with detector areas smaller than Ø 0.4 mm, the use of fiber adapters is only recommended to a limited extent, since coupling losses and instabilities can occur. If the focus is on high-precision fiber optic measurements, using FC-models with fixed optical fiber input will usually give the best results.
All HCA-S photo receivers with free space input are equipped with UNC 8-32 and M4 threaded holes and can therefore be conveniently and stably integrated into optical systems on standard rod holders. The optionally available adapter plate PRA-PAP opens up further mounting options.
Applications
- Spectroscopy
- Fast pulse and transient measurements
- Optical triggering
- Optical front-end for oscilloscopes, A/D converters and RF lock-in amplifiers
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