Zero warm-up laser

What it does

Zero Warm-up Source optical architecture improves optical light source performance, measurement accuracy & work practices.

It is unique in the industry, and only adds a modest extra cost for performance-critical users.

User benefits

Improved source stability during emitter warm up. Most users will see effectively zero source drift due to warm up.

Improved source stability over temperature. Particularly useful for long term monitoring.

Improved source stability under varying ORL conditions.

Highly stable eLED SM source option for high stability loss testing or CD testing


Laser / LED thermal power stability is critical for source stability. The performance is to be found in data sheets for laser devices under something like "tracking error". A"typical" specification is between ±0.5 - ±1 dB over temperature range of say -20 to 50°C.  A batch of lasers will show quite different individual characteristics, so sample testing the performance of one instrument may not be representative: it's easy to cherry-pick a great sample.

If an instrument is used in a very stable temperature, then this issue largely shows up as "warm up" drift. However if its used in a typical instillation environment, then output power can drift substantially, and this performance will depend on the particular s/n of instrument used.

We have found that for lower specification Kingfisher sources, the thermal stability specification is ±0.6 dB over a temperature range of 70 °C. Many competitor sources wouldn't achieve this.

For example, a user takes our source from an air conditioned car at say 20 °C, and gets out into either the desert heat at say 40 °C, or a cold day at say 0 °C. The change of 20 °C can easily induce an instability of say 20/70 x 0.6 dB = ±0.17 dB. while the instrument temperature changes over say 20 minutes. 

Optical Laser Light Source Stability over time and temperature

Even in a laboratory environment, if the sun swings round onto a bench with the instrument, or the air conditioner turns off at the end of the day, then sensitive experiments can vary significantly.

The unique Kingfisher Zero Warm Up Source has a much tighter stability specification of ±0.2 dB over temperature. The equivalent instability in the example given, would be 20/70 x 0.2 dB = ±0.06 dB.

Warm up stability

Warm up stability is essentially a sub-set of stability over temperature. In other words, after turn-on, the laser device warms up by a few degrees over 10 - 20 minutes. This can vary substantially between identical p/n instruments..

Assuming a laser device tracking error of say 0.6 dB, and a laser device warm up of say 5 °C, then the warm up drift would be 5/70 x 0.6 dB = ±0.04 dB. However for a Zero Warm-up device, it will be about 0.014 dB.

The irritating thing about this warm-up, is that it happens every time the particular laser is turned on, eg any time the source wavelength is changed, and not just at instrument turn-on. This can seriously affect productivity of users testing at multiple wavelengths. Autotest helps significantly here, since all lasers are kept on continuously at eg 50% duty cycle.

The majority of instruments dodge the issue by only specifying stability "after warm-up", and with a very tight ambient temperature variation, effectively in an environmental chamber.

The Zero Warm up Source architecture reduces warm up drift to a negligible level.

Long / Short term stability

This often quoted light source specification is really just another way of looking at thermal stability. It is usually measured and specified in such ideal circumstances (eg in an environmental chamber, after warm up) as to not usefully represent what a user will achieve "on the job". We quote this on our data sheets to allow comparison with other products, however it's not a very dependable specification in practice.

Optical return loss stability

The power output of all laser sources (that don't incorporate an isolator) is affected by return loss. Our experiments indicate a dependence large enough to affect precision loss testing.

The real problem is that as the source is moved between test items with differing ORL, the source power varies a bit, and so the loss measurements vary a bit. The user is usually unaware that this is happening.

Effect on work practices & test procedures

Practical Work practices and test procedures have to take into account the reasonable worst-case performance of both people and equipment. Therefore, equipment specification limits are more important than "average" performance. In this situation, the tight specifications of the Zero Warm Up sources are a clear winner when it comes to test uncertainty.

Obviously, if warm-up delays can be avoided, then much more work can be done in the same time, with greater confidence.

Zero Warm-Up Laser Instruments

KI 9600A Pocket Power Meter

  • Simple shirt-pocket size power meter
  • Options for all networks & users
  • Low-skill TamperLock mode
  • Ideal for transmission installers
KI 2600 Handheld Power Meter

  • Productivity power meter
  • Options for all networks & users
  • Ideal for cable installers
  • Powerful reporting capability
  • Optional VFL
KI 6102 GPON / PON Power Meter

  • Economical in-line meter for PON test
  • Simple and reliable operation
  • 1310 / 1490 / 1550 nm, two ports
  • 100 test memory with PC software
KI 6106 10G/XG PON Power Meter

  • Economical in-line meter for PON test
  • Simple and reliable operation
  • 1270 / 1310 / 1490 / 1577 nm, two ports
  • 100 test memory with PC software
KI 9800A Pocket Fiber Source

  • Economical shirt-pocket size source
  • Options for SM, MM, POF etc
  • Low-skill TamperLock mode
  • MM is EF compliant
  • Eye safe high power VFL 5 mW
KI 6300 Pen Visual Fault Locator

  • Pen-sized universal laser VFL 1mW
  • Eye safe class 1 laser
  • LC / 1.25 mm universal adapter option
KI 2400 & 2800 Handheld Source

  • Versatile productivity source
  • Options for SM, MM, POF etc
  • SM + MM quad up to 6 λ
  • Unique VisiTester VFL
  • ISO 17025 traceable
KI 6610 FiberSafe Microscope

  • Microscope for inspection of SM, MM, MPO and POF networks
  • Best quality, image & eye safety
  • Wide range of interchangeable adaptors
  • Many helpful features


KI 6680 Fiber Inspection Probe

  • Scope to check mated & unmated connectors SM, MM, MPO
  • Software for Windows, Apple or Android devices
  • Wifi or USB connection
  • Easy operation


OPT684 FiberSafe Microscope Digital Image Capture Option

1.3 Mpixel camera with USB connection. For all models of FiberSafe Microscope. This unit requires MS Windows to install the drivers.

KI 23400 & 27400 Handheld Two-Way Loss / Length / ORL Test Set

  • Fastest & most accurate certifier
  • Bi-directional loss, ORL & length on one fiber
  • SM, MM & quad versions
  • Pass / fail display
KI 2300 & 2700 Handheld Loss Test Set

  • Versatile Loss Test Set
  • VFL-VisiTester option
  • SM, MM & Quad versions
  • MPO CS POF versions
KI 7010 Series Variable Optical Attenuator

  • SM, MM & POF versions
  • Best optical specifications
  • Easy to use, rugged & reliable
  • Remote control vis RS232
KI 6170 Clip-on fiber identifier

  • Clip-on to check for traffic or test tones
  • Low false detection rate
  • Optical Power display 
  • Requires a light source with tone facility

POF air-gap collimator assembly useful to place bulk optics devices, sensors or samples into plastic optical fiber light path.

G2 Panel Mount Connector Series

  • Universal Optical Connector for OEM, test & production
  • For connectors with 2.5 & 1.25 mm ferrule, SMA, POF and others
Miscellaneous Accessories

Various accessories and kit components for Kingfisher testers.

MPO Patch Cords & Test Leads

Test Grade MPO Patch Leads to improve your test accuracy

Fiber Test Leads

Test Grade SC and LC Patch Leads to improve your test accuracy

Single mode, multimode, PC, APC

Hybrid Adaptor Series

  • Sources, attenuators, OLTS
  • Most power meters except XL series
  • G2 connector
  • Useful to make test adapter leads
XL Series Power Meter Adaptor Series

  • Large area XL series power meters
  • Legacy KI6000 power meters
  • Also fits other instruments
KI66xx Microscope Adaptor Series

  • KI661x FiberSafe Optical Microscope
Cold Clamp

  • Use liquid nitrogen to induce a non-destructive optical marker
  • Use with OTDR to localize physical fault within 1m
  • Significantly improve real-world response & labor time
  • Works on live systems
Standard accessories

Various standard accessories that come with the products.