Independent industrial and scientific laser service · New Jersey Mon–Fri 8:00–18:00 ET service@phasexlaser.com
Technology

Picosecond laser repair and diagnostics

Independent evaluation and repair engineering for seeded picosecond sources, amplified fiber and solid-state platforms, and the conversion stages built on top of them. The work starts by establishing where in the chain optical power stops existing.

ArchitectureSeed, amplifier chain, pump, feedback, conversion
MethodMeasure the beam, not the display
OutcomeWritten findings before repair
Orientation

The architecture that matters for diagnosis

Picosecond systems from different manufacturers look nothing alike from the outside and are remarkably similar inside. For diagnostic purposes the useful model is a chain, and the job is to find the link where optical power stops.

  1. Seed. A diode or oscillator generating the pulse, with a high-speed driver defining its timing and amplitude.
  2. Preamplifier. First gain stage, frequently fiber-based, with its own pump and protection.
  3. Power amplifier. The main gain stage, and in fiber systems the section carrying the most optical stress.
  4. Optical path hardware. Splices, pump combiners, isolators, mode-field adaptors, connectors and delivery fiber. No electrical signature when they fail.
  5. Conversion stage. Where present, an SHG or higher harmonic stage with a temperature-controlled crystal.
  6. Feedback and control. Monitor photodiodes, converter stages, control loop, interlocks, trigger and communication.

Almost every difficult picosecond fault comes down to one question: is the problem upstream or downstream of a given point in this chain. Everything on this page is organized around answering that question cheaply and in the right order.

Failure symptoms we are asked to evaluate

01

No output or output at the detector noise floor

The system powers up and reports normally while measured power is a small fraction of expected, or indistinguishable from background.

02

Setpoint changes but optical power does not

Commanded values change the displayed reading with no physical effect. A command-path or protection-state problem until proven otherwise.

03

Timing normal, no optical pulse

Repetition rate and sync outputs behave correctly. The timing electronics are alive. The optical chain may be entirely dead.

04

Gradual power decline over weeks or months

Pump diode degradation, progressive fiber-interface damage, contamination or a slow drift in the feedback path.

05

Unstable or intermittent output

Power that fluctuates, drops out and returns, or depends on ambient temperature. Thermal control, connector integrity and marginal driver behavior.

06

Pulse-train structure wrong

Missing pulses, amplitude modulation across the train, incorrect response to external trigger, or master and slave synchronization that will not lock.

07

Converted output low, fundamental present

The genuine conversion-stage case, distinguished from all of the above by the fundamental power confirmed at the stage input.

08

Trips, faults and silent limits

Protection states that shut the system down, and protection states that quietly cap it without reporting anything.

Is this what your system is doing?

Send the model, a photograph of the product label and the symptoms. We review it and respond with the next step.

Four diagnostic traps

These four are worth eliminating before anything invasive happens, because each one can produce a symptom that looks like a different fault.

1. The displayed value is not a measurement

Many systems display the commanded setpoint rather than a sensed value. If the command reaches the display layer but not the current driver, the panel reads perfectly while nothing changes physically. Measure the drive current at the hardware and establish whether the readback path is a measurement or an echo.

2. Timing is not lasing

The trigger and synchronization electronics run independently of the optical chain. A clean repetition-rate reading and a healthy sync output confirm the timing board. Whether optical pulses exist is a separate measurement made with fast photodetection on the real beam.

3. The wrong detector produces confident nonsense

A fiber-coupled power meter used on a free-space beam collects an unknown fraction of the light. A sensor calibrated at one wavelength misreports another. A detector operated near its noise floor produces a number that looks like a measurement and is not. Before any small reading is interpreted, the noise floor has to be established and the measurement repeated with calibrated free-space detection and wavelength-selective optics.

4. The last stage is blamed for the first stage

When a system with a conversion stage produces low visible output, the crystal is the intuitive suspect and usually the wrong one. Second-harmonic generation cannot produce more than the fundamental delivered into it. If the converted reading and the fundamental reading are of the same order, the arithmetic does not describe a working conversion process, and the real question is what is happening upstream. This is covered in detail on the SHG and harmonic generation page.

How we localize the fault

  1. As-received condition report. Configuration, labels, connections and shipping condition recorded and photographed before anything is changed.
  2. Configuration verification. Every module label read separately. What the system is takes precedence over what the record says it is.
  3. Bring-up and infrastructure. Supplies, cooling, interlocks, protection states and control communication established, and readback values checked against physical measurement.
  4. Measurement and fault localization. Output characterized by wavelength on a defined path, the optical pulse train verified, and the chain divided until the fault sits in one subsystem.
  5. Written findings and your approval. What was measured, what was found, what remains unknown, and the repair options with their cost and risks. Nothing is repaired, substituted or modified until you approve the scope in writing.
  6. Repair, validation and return. Work inside the approved scope, then electrical, optical, timing and functional validation, a written service report and documented packing.

Measurements defined per project

Every engagement names its measurements before it starts. PhaseX defines and provides the measurement capability the project requires. Depending on the system and the question being answered, that is owned, rented or qualified third-party measurement resources arranged as required. The evaluation proposal states which measurements will be made, by what method, and where each one comes from, together with the acceptance criteria the work is judged against.

MeasurementWhat it establishes
Drive current against commandWhether a commanded setpoint reaches the driver and produces real current, which separates a control-path fault from an optical one
Supply, rail and protection behaviorRail integrity under load, sequencing, and protection states that cap output without reporting anything
Timing, trigger and switchingTrigger and synchronization paths, driver and Pockels cell switching, and pulse-train structure
Optical power and pulse energy by wavelengthReal output at each wavelength on a defined and terminated path, with the detector, wavelength response, attenuation and measurement point stated
Optical pulse presence and repetition rateWhether an optical pulse train exists at all, and its relationship to the trigger
Spectral conditionEmission wavelength and bandwidth, and confirmation that the light being measured is the light assumed
Beam and mode conditionSpatial condition of the output, and evidence of optic, fiber or alignment damage in the delivery path
Thermal behavior under loadCooling loops, TEC and oven control, and thermal derating that presents as a silent power limit
Pulse duration and beam qualitySpecified where the project requires it, and performed with the measurement resource identified in the proposal

In-house instrumentation currently includes a RIGOL MHO984 oscilloscope and a Joulescope JS320 for electrical, current, timing and pulse-train work. Optical metrology is specified per project and provided through owned, rented or qualified third-party measurement resources arranged as required and named in the proposal. We do not publish an equipment inventory in place of a measurement plan, and we do not offer manufacturer-equivalent calibration or certification to original published specifications where the original acceptance data and the corresponding standards are unavailable.

Systems covered

We provide independent service and repair support across seeded and amplified picosecond platforms, including the manufacturers below.

Onefive / NKT KATANAOrigamiEKSPLA AtlanticEKSPLA PL seriesLight Conversion PHAROSLight Conversion CARBIDECoherent MonacoSpectra-Physics IceFyreSpectra-Physics TalonAmplitude SatsumaLumentum / Time-BandwidthTOPTICA FemtoFiberMenlo Systems fiber platforms
What we confirm first

We provide independent service and repair support across the platforms below. Configuration, parts access and required metrology decide the scope of a given job. Tell us your configuration and we will confirm the scope and the shipping list.

Dedicated manufacturer pages: Onefive / NKT KATANA. Additional manufacturer hubs are published as the underlying documentation is verified.

Required shipment components

  • Laser head
  • Controller
  • Power supply
  • All interconnecting cables, including any with a non-standard pinout
  • Any dedicated module required for normal operation, including conversion, trigger or paired excitation units
  • Control software, license files and interface documentation, including a MATLAB control path where that is how the system is driven
  • Manuals, configuration sheets, acceptance data and prior service reports, however incomplete

A system that cannot be brought to its normal operating state on the bench cannot be diagnosed. We receive systems from outside the United States and will provide the commercial documentation a repair shipment normally requires, but customs classification, duties and clearance timing remain the sender's responsibility and we do not give customs guarantees.

Scope and safety

  • PhaseX is not a factory-authorized service center for any manufacturer named on this page.
  • No repair is guaranteed before evaluation. A finding that a system is not economically repairable is a legitimate result and is delivered in writing.
  • We do not perform manufacturer-equivalent calibration, and we do not certify to original published specifications without the original acceptance data and the corresponding standards.
  • We do not claim service experience on a configuration we have not actually worked on.

Class 4 work is planned and executed under a project-specific laser safety plan. The required engineering controls, personal protective equipment, beam management and facility conditions are defined in writing before any energized optical work begins, and the infrastructure that plan calls for is provided within the project scope. Where a laboratory's own controls are involved, final hazard analysis and approval stay with the institution's LSO or EHS function.

Independent service

PhaseX Laser Services is an independent third-party service provider and is not affiliated with, authorized by, or endorsed by the manufacturers listed unless expressly stated in writing. Brand names and model names are used only to identify equipment for which customers may request evaluation.

Related pages

Next step

Tell us what you measured and how you measured it.

On picosecond systems the measurement method is as important as the number. Send the model and serial label photographs, your normal operating parameters, the symptoms, and the instrument and beam arrangement you used. We will tell you whether an evaluation is worth your shipping cost.

Request service
Contact

Talk to an engineer, not a call center

Phone
(551) 379-6083
Email
service@phasexlaser.com
Bench
239 New Road, Suite B210Parsippany, NJ 07054
Hours
Monday–Friday8:00–18:00 ET
Request service Call Email