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

Laser diode and pump driver repair

Component-level repair and evaluation for the electronics half of a scientific laser. Drivers, supplies, thermal control, feedback paths and interlocks, which is where many no-output faults are found.

The pivot testCommanded current against actual current
Good news for old systemsElectronics can be repaired when optics cannot
DeliverableWritten findings before any repair
Orientation

The electronics fail more often than the optics

Laboratories tend to think about scientific lasers optically, and to assume that a system producing no light has an optical problem. In practice, on sealed and alignment-free platforms, a significant share of failures sit in the electronics: the drivers that set current, the supplies that feed them, the thermal control that keeps everything in range, and the feedback that tells the system what it is doing.

This is good news for an obsolete instrument. Electronics are built from components that can be identified, measured and in most cases obtained or substituted. An optical assembly aligned at manufacture may be unrecoverable once it fails. A driver board almost never is.

It is also the reason a laboratory can spend weeks chasing an optical fault that was never there. The symptoms overlap almost completely: no output, low output, unstable output, output that will not respond to commands. Separating the two is a measurement question, and it is cheap to answer if it is answered first.

What we repair at this level

01

Laser diode drivers

Current regulation, compliance, ripple and noise behavior, soft-start and shutdown sequencing, and the protection circuits that cap output without reporting anything.

02

High-speed seed drivers

In seeded picosecond and nanosecond architectures, the driver that defines pulse amplitude and timing. A failure here produces a system that is electrically and thermally perfect and optically dead.

03

Pump current controllers

Multi-channel pump drivers, current sharing between channels, and the case where one channel of several has failed and the system simply runs weak.

04

Pockels cell drivers

High-voltage switching and its timing. In regenerative amplifiers, this decides whether a pulse is amplified, partially amplified or not at all.

05

Power supplies and rails

Main and auxiliary supplies, rail sequencing, holdup and ripple. Aging electrolytic capacitors are an expected finding in supplies of this age.

06

Thermal control electronics

TEC drivers, temperature sensors and their conditioning, control loops, fan and chiller interfaces. A thermal fault normally presents as a silent power limit rather than as a temperature alarm.

07

Feedback and monitoring paths

Monitor photodiodes, transimpedance and conditioning stages, analog-to-digital and digital-to-analog converters, and the control loop. Both failure directions occur: a healthy laser reporting a false low value, and a degraded laser reporting a healthy one.

08

Interlock and protection chains

Interlock loops, shutters, key switches, remote interlock connectors and emergency stops. Frequently the cheapest branch to eliminate and frequently the actual answer.

09

Trigger, gating and synchronization

External trigger inputs, delay generators, master and slave paths, and the timing relationships between them.

10

Control interfaces and communication

Serial, USB and Ethernet interfaces, protocol handling, and the software path including MATLAB and LabVIEW control. A dead interface on a working laser is a repairable fault that reads as a dead laser.

11

Cabling and connectors

Non-standard cables, custom pinouts and degraded high-current or high-voltage connectors. A single point of failure that is straightforward to rebuild once the pinout is established.

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.

How we separate electronic from optical faults

The order matters, and it is designed so that the cheap tests come first.

  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.
Why this measurement comes early

Comparing commanded current against actual current at the hardware divides the machine in half. If the command produces real current, the electronics have done their job and the work belongs in the optical chain. If it does not, the work belongs here. It is quick to establish on the bench, which is why it sits early in our sequence rather than late.

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.

Obsolete parts, substitution and retrofit

On a discontinued system the original board frequently does not exist any more. There are three routes, and the right one depends on the instrument and its remaining service life.

  1. Component-level repair. The original board is repaired. The least invasive route and the first one we assess.
  2. Functionally equivalent substitution. A current component matched on the parameters that matter for the circuit and the application, fitted to the original assembly.
  3. Engineered replacement. Where no repair or drop-in equivalent exists, a driver, supply, thermal controller or interface designed to perform the original function within the original envelope, with the original protection behavior reproduced.
Documented as a deviation

Any substitution or engineered replacement is recorded in the service report as a deviation from original design, with what was fitted, why, and what behavioral differences to expect. That record belongs in your instrument file. A laboratory that does not know its laser has been modified will eventually be misled by its own documentation.

Where we stop

  • A custom assembly with no available substitute and no realistic path to engineering one within the value of the instrument.
  • A potted, encapsulated or sealed assembly that cannot be opened without destroying it, where no replacement exists.
  • A high-voltage or high-energy assembly whose safe reproduction we cannot verify. We will not return an instrument whose protection behavior we are not confident in.

Systems this work applies to

Driver, supply, thermal and control electronics are common to almost every scientific laser architecture, which makes this the broadest service we offer. We do this work on the electronics of:

Seeded picosecond and nanosecond fiber platformsTi:Sapphire oscillators and amplifiersDiode-pumped solid-state CW and pulsed platformsFiber and Yb femtosecond platformsFlashlamp-pumped Nd:YAG and Nd:YLF systemsSupercontinuum and single-frequency fiber sourcesParametric modules with oven and stage controlScientific diode laser and tapered-amplifier systems

Manufacturer-specific context is on the Coherent, Spectra-Physics, Onefive / NKT KATANA, Light Conversion, Continuum / Lumibird, EKSPLA and Litron pages.

What we confirm first

Send us your configuration and we will confirm the scope. Send photographs of the board or assembly if you have already opened the unit, and tell us what you measured. On electronics faults that information frequently shortens the evaluation considerably.

Required shipment components

A system that cannot be brought to its normal operating state on the bench cannot be diagnosed. For bench evaluation we normally need:

  • 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, pump or paired units
  • Control software, license files and interface documentation, including a MATLAB or LabVIEW control path where that is how the system is driven
  • Manuals, configuration sheets, acceptance data and prior service reports, however incomplete

On discontinued platforms the customer's own paperwork is frequently the only surviving record of the configuration. Send it even when it looks irrelevant.

International shipments

We receive systems from outside the United States, including from Canadian universities and research institutes. We provide the commercial documentation a repair shipment normally requires and coordinate with your shipping office. Customs classification, duties, temporary import treatment and clearance timing remain the sender's responsibility, and we do not give customs guarantees. Insurance is the sender's decision and should reflect replacement value. We document the as-received condition on arrival, which is the evidence you would need if transit damage has occurred.

Scope and safety

Two limits

We are direct about the work we take on, so we are equally direct about the two boundaries.

  • We do not promise a specific repair before diagnosis. The diagnostic evaluation comes first and the repair scope follows from it. A finding that a system is not economically repairable is a legitimate result, and it is delivered in writing.
  • We do not certify a system to original published specifications where the original acceptance data and the corresponding standards are unavailable. We document the measured condition on arrival, the fault found, the work performed, and the measured condition on completion.

Warranty

If your system is still inside its manufacturer warranty, use the manufacturer, or get written authorization from the seller first. Our work is out-of-warranty and legacy equipment, which is where the support gap sits in any case.

Laser safety

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, not affiliated with or authorized by any manufacturer named on this page unless expressly stated in writing. Brand and model names identify equipment only.

Next step

If you have already opened it, send the board photographs.

On electronics faults, photographs of the assembly and a description of what you measured frequently shorten the evaluation considerably. Send them with the model and serial label photographs and what the system does now.

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
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