FIBER OPTIC TRANSLATORS

Product Brief (PDF, 2 pages)

This is a broad product line of fiber optic transmitter (E to O), receiver (O to E), transceiver (both), and wavelength converter (O to E to O) functional test instruments, collectively called “fiber optic translators”. Models can contain 1 to 16 channels of analog and/or digital fiber optic transmitters and/or receivers with many related optical and electrical options, offering customers millions of possible models. Wavelength converter models can be provided in 1R (linear analog), 2R (limiting analog), and 3R (CDR digital regeneration) configurations. Special analog transmitter and receiver models can be provided with calibration data for use with electrical network analyzers to add O-O, E-O, and O-E test capabilities. See the TME “Fiber Optic Triggers” for specialized receiver models that provide single or multi-rate clock-recovered trigger signals for high-speed optical sampling oscilloscopes.

A variety of wavelengths, fiber types, and electrical I/O choices can be accommodated for each channel. Popular fixed wavelengths include 850 nM, 1310 nM including CWDM channels, and 1550 nM including WWDM channels and S-C-L band DWDM channels on 100, 50, or 25 GHz ITU grid spacing. Tunable transmitter and/or receiver wavelengths are offered for 1550 nM C and L bands on 100, 50, or 25 GHz ITU grid spacing. Popular fiber types include multimode 50 and 62.5 micron fiber (850 nM and 1310 nM) and single mode standard fiber (1310 nM and 1550 nM). Electrical inputs and outputs can be single-ended or differential and AC or DC coupled (single-ended, 50 KHz, AC coupling default). Independent O to E and E to O single-ended polarities are offered with fixed positive (default), fixed negative, or programmable translation polarity. Special wavelengths (such as 980 nM or Raman pump wavelengths), fiber types (such as polarized or plastic), and electrical options can be provided upon request.

Fiber optic transmitters are offered with various modulation methods, wave shapes, speeds, and power levels. Modulation methods include direct, electro-absorptive (EA), and Lithium Niobate (LiNbO₃) modulation. Wave shapes include linear analog and digital NRZ, RZ, and CRZ shapes with programmable extinction, contrast ratio, and chirp control respectively. Analog bandwidths from ~50 MHz to ~40 GHz and digital speeds from ~50 Mb/s (OC1) to ~43 Gb/s (OC768 + FEC) are offered. Optical power outputs from –15 dBm to +10 dBm are offered, depending on wavelength and speed limitations.

Transmitter options include SBS Suppression (for long fiber span + optical amplifier tests), channel identification tone generation (for multi-channel testing), and controlled output levels via Variable Optical Attenuator (VOA) and Tapped Coupler Power Monitor (for product under test receiver sensitivity tests or DWDM channel matching). Special multiple output configurations are offered where several different transmitters are driven by one electrical input, either one at a time (selector function) or at the same time (splitter or fan-out function). Special transmitter modulation methods, wave shapes, speeds, and power levels can be provided upon request.

Fiber optic receivers are offered with various detector types, speeds, optical dynamic range, and circuit structures. Detectors include silicon, GaAs, and InGaAs PIN or APD photodiode types, depending on operating wavelength. Analog bandwidths from ~50 MHz to ~40 GHz and digital speeds from ~50 Mb/s (OC1) to ~43 Gb/s (OC768 + FEC) are offered. Optical dynamic ranges are offered from –38 dBm to –7 dBm sensitivity and –7 dBm to +3 dBm overload power, depending on wavelength and speed limitations. Analog output circuit structures are offered having one or more insertable linear fixed gain amplifiers (for dynamic range control) and/or one or more insertable low pass filters (for SONET, Fibre Channel, etc. eye pattern mask testing). Digital clock and data output circuit structures are offered having single or multiple rate clock-data recovery (CDR) circuits and limiting amplifiers. Any data rate between 10 Mb/s and 2.7 Gb/s or 9.3 Gb/s to 12.9 Gb/s is offered with other rates upon request. Circuit structures with both analog outputs and per channel or selected channel digital CDR outputs are offered. This structure is used to drive an Agilent ParBERT™ error detector (analog and clock trigger) or an electrical oscilloscope (analog and clock trigger) and error detector (data and clock) for eye pattern and BER tests.

Receiver options include use of fixed or tunable or lock-on optical filters, channel identification tone detection (for multi-channel testing), and receiver photodiode or tapped coupler power monitor options (makes extinction ratio tests possible with Agilent ParBERT™. A multiple input configuration is offered where one of several different receivers are selected to drive one electrical output. Special receiver CDR data rates and programmable CDR thresholds can be provided upon request.

Other options include various arrangements of optical amplifiers (EDFA or SOA), attenuator, coupler, power monitors, scramblers, polarizers, etc. Connector options include front or rear panel mounted or special optical and/or microwave I/O connectors. Switching options include optical and/or microwave module passthru, bypass, loop back, or selector switches. Electrical options include inclusion of FEC encoding and/or decoding, time or wave division MUX and/or DMUX, amplified data/clock electrical I/O (signal level boosters), and data-to-clock phase shifters (for SONET/SDH analyzers).

An example test system using TME equipment can be created and deployed at one or more telecom central offices for automatic DWDM network trunk line quality of service (QOS) testing “one lambda at a time”. Multiple network DWDM trunk lines can be accessed in duplex or simplex with low loss optical tap couplers. The tapped lines are routed to a special TME transceiver containing optical switches to select the proper tapped lines, optical amplifiers to boost the low tapped optical power levels, a fiber optic transmitter, and a fiber optic receiver. The transmitter is a ~10 Gb/s 1550 nM C-band tunable NRZ laser with VOA, optical power monitor, and SBS suppression. The receiver has a 1550 nM C-band tunable filter with optical power monitor, a 9.953 Gb/s or 10.709 Gb/s clock-data recovery circuit, and an analog output with insertable low pass filter and insertable gain amplifiers. The transceiver is connected to an Agilent ParBERT™ (or a BERT and sampling oscilloscope) and schedule or demand controlled by a computer with a test program. The computer signals the central office equipment to re-route traffic for one color at a time in either duplex or simplex mode. The computer signals the transceiver and ParBERT™ to select the proper trunk lines and transmit and receive one wavelength at a time for BER, optical power, sensitivity, and eye pattern testing. In duplex mode, pattern generation and error detection is done at the same central office using far end loop-back. In simplex mode, pattern generation is at the near end central office and error detection is at the far end central office.

FIBER OPTIC TRIGGERS

Product Brief (PDF, 2 pages)

This is a product line of fiber optic sampling oscilloscope trigger test instruments. Clock recovery technology is used to extract an electrical trigger signal from an 850 nM, 1310 nM, or 1550 nM fiber optic signal sent to an optical sampling oscilloscope, such as those made by Agilent, Tektronix, and others. Models are offered for 850 nM multimode, 1310 nM multimode, 1310 nM single mode, or 1550 nM single mode operating wavelengths. Various ~10 Gb/s models are offered with 1 to 6 separate fixed value trigger rates at any rate between 9.3 Gb/s and 12.9 Gb/s. Lower trigger rate models are offered with programmable trigger rates between 10 Mb/s and 2.7 Gb/s operation. Other model variations add an analog electrical data output for input to an electrical channel of a sampling oscilloscope or a digital output for operating an error detector. Several amplification options are offered to improve the optical input sensitivity.

FIBER OPTIC SPANS

Product Brief (PDF, 2 pages)

This is a product line of programmable Fiber Optic Span functional test instruments.  These instruments function as “programmable telecom superhighway in a box” by providing programmable optical chromatic dispersion, dispersion compensation, and amplification.  Models accomplish this by using various arrangements of one or more single mode optical fiber types, dispersion compensating fiber, dispersion compensators, optical switches, optical amplifiers, optical filters, etc.  For example, one single mode C-band model provides –2000 pS/nM to +3200 pS/nM (200 KM) in 100 pS/nM (6.25 KM) steps at 1550 nM using standard single-mode fiber, dispersion compensating fiber, optical switches, and C-band DWDM optical amplifiers.  Multimode models can be provided upon request.

FEC TRANSLATORS

This is a product line of electronic transmitter, receiver, and transceiver functional test instruments that perform Forward Error Correction (FEC) on ~2.5, ~10, or ~40 Gb/s telecom signals.  Models with 1 to 4 channels for ~10 Gb/s telecom signals are offered for SONET/SDH (9.953 Gb/s) or 10G Ethernet (10.3 Gb/s) data rates to G.975 (10.664 Gb/s), G.709 (10.709 Gb/s), or SuperFEC (~12.4 Gb/s) data rates with several options.  Models for ~2.5 Gb/s signals are available on request and models for ~40 Gb/s signals will be offered as components become available.

ELECTRONIC TRANSLATORS

This is a product line of electronic transmitter, receiver, and transceiver functional test instruments that convert, split, or select signals between common analog coax and/or digital logic levels and telecom formats.  Common analog signals include single-ended and differential 50, 75, and 100 ohm signals that are input or output for test or measurement equipment.  Common digital signals include CMOS, TTL, ECL, and other logic levels.  Common telecom signals include DS1, DS3, and other formats.  Example products are (1) a 4 channel RJ45-8 to SMA, linear, DC-1 GHz, 100 ohm differential to 50 ohm single ended converter for use as an oscilloscope front end, and (2) a 1 channel 3.5mm, limiting, 100 KHz-10 GHz differential to single ended converter for BERT or jitter testing.

TELECOM SWITCH MATRICES

This is a product line of multi-channel, telecom specific RF, microwave, and fiber optic switch matrices.  A switch matrix is commonly used to route fiber optic, microwave, RF, DS3, DS1, or other telecom signals between telecom products and functional test equipment.  Switch topologies include loop-back, daisy chain, daisy bypass, float, terminate, short, and channel access for performance tests.  Conventional cross-connect, transfer, and selector switch matrices are also offered.

MR. HORIZON TEST FIXTURE SYSTEM

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