Specifications: Parameters measured: Numerical Aperture (NA) Mode-Field Diameter (MFD) Angular Widths Angular Width Ratios Angular Position Intensity or Amplitude Relative Integrated Power Relative Power in user-specified cone angles about an arbitrary axis Accuracy: NA: <±1% MFD: ±5.0% for a normal 10 µm fiber Angular width: <±0.055° Scan range: ±72° Scan radius: 84 mm Scan time: Single scan update: 5 Hz 3D scan: ~10s-100s (depends on # of scans) Dynamic range: >36 dB Spatial sampling resolution: 0.055° Spectral range: InGaAs detector: 800-1700 nm Software: Windows 95/98 Windows NT 4.0 ActiveX Automation server capability Scan unit dimensions: 206 x 165 x 190 mm Scan unit weight: ~6 kg

Photon's LD 8900R Wide Dynamic Range Goniometric Radiometer characterizes the angular radiation intensity of light. The LD 8900R provides direct real-time far-field measurements with >36 dB dynamic range, angular sampling resolution of 0.055° and a field-of-view of ±72° (144°). The LD 8900R is ideal for characterizing the light flux from many sources, including VCSELs, laser diodes, optical fibers, optical waveguides, and more.

The LD 8900R provides full three-dimensional measures of the far-field pattern in minutes or less, with far better resolution than a CCD camera. Measurement of the Mode-Field Diameter of optical fiber is now possible in real time with greater than 5% accuracy.

Wide Dynamic Range
The LD 8900R has all the features of the LD 8900, except with a wider dynamic range, greater than 36 dB, compared to the standard 24 dB. This wider dynamic range provides greater detail in the "tails" of the far-field pattern.

The LD 8900R is available with either a silicon detector or an InGaAs detector, and has a standard entrance aperture of 2 mm, with an optional 10-mm entrance aperture for use with larger sources such as LEDs and LD bars. The LD 8900R is a modular unit designed for R&D, manufacturing, and custom applications, such as testing LDs at the wafer level.

Mode Field Diameter in Real Time
The LD 8900R allows for real-time measurements of Mode Field Diameter (MFD) with an accuracy of ±5% for a nominal 10-µm single-mode fiber. Mode Field Diameter (MFD) of single-mode fiber is measured using the methodology described in the TIA/EIA Standard FOTP-191. Specifically, the MFD is calculated using the Petermann II integral, with data sampled at angular resolution of 0.055° and collected over an angular extent of ±72° (144° viewing angle).

The complete system includes:

• The Scan Unit
• The Motion Control Module
• PC (monitor is user supplied) with the Goniometric Radiometer Model GS880 Scan Control and Data Acquisition Card installed
• Goniometric Radiometer Acquisition and Analysis Software for user-specified MS Windows versions 98 and later.
• Power and Instrument Cables

An optional LD 8900R semi-custom source mount, specifically designed to meet your application needs, can be quoted upon request. The Wide Dynamic Range version is also available for the Model LD 8800.

LD 8900R Applications

Measure:

• Mode Field Diameter
• Numerical Aperture
• Scatter pattern of a transmitting diffuser
• Optical waveguides
• Influence of elements in the light domain, e.g., lenses, filters, waveguides
• Pigtailed light sources
• Single- and multi-mode fiber

Optimize:

• Collimation:
• Laser diodes
• GRIN lenses
• Coupling of energy:
• Fiber
• Cavity
• Lenses
• Detectors
• Array waveguides
• Dispersion compensating elements
• WDM mux/demux
• Other optical elements