What are the main types of optical delay lines and how do they differ technically?

Common types include free-space delay lines (using mirrors/retroreflectors on translation stages), fiber-based delay lines (using spooled or variable-length fiber), and integrated photonic delay lines (using waveguide spirals or cascaded resonators). Free-space designs typically allow continuous, high-precision tuning over centimeters to meters of path, while fiber and integrated solutions are more compact, stable, and better suited for long fixed delays or multi-channel implementations.

How do key concepts like group delay, dispersion, and coherence affect the performance of an optical delay line?

Group delay defines the actual temporal shift experienced by modulated signals, and is set by the product of group index and physical path length. Dispersion in fiber or waveguides causes pulse broadening as different spectral components experience different delays, which is critical in ultrafast and high-bit-rate applications; coherence length of the source limits the maximum useful delay for interferometric measurements, since delays longer than the coherence length wash out interference fringes.

What technical parameters should I consider when selecting an optical delay line for my application?

Key parameters include delay range (or equivalent path length), delay resolution/step size, insertion loss, polarization dependence (PDL, PMD), return loss, and operating wavelength band (e.g., 800 nm, 1064 nm, C-band). For dynamic applications, you should also consider tuning speed, mechanical repeatability, environmental stability, and power handling if using pulsed or high-average-power lasers.

How do I compare different optical delay lines in terms of accuracy and stability?

Compare the specified delay accuracy (often given in femtoseconds or micrometers of path), repeatability over multiple cycles, and thermal drift over the operating temperature range. Mechanical designs with precision linear stages and feedback encoders, or fiber-based units in temperature-controlled housings, typically provide better long-term stability and lower timing jitter than simple manual or open-frame assemblies.

What are typical lead times, customization options, and cost drivers for optical delay lines?

Standard catalog delay lines with fixed ranges and common wavelength coatings may ship within 1–3 weeks, while custom ranges, specialty wavelengths, or vacuum/ultrafast configurations can extend lead times to 4–8 weeks or more. Major cost drivers include delay range, required precision, optical coating complexity, fiber type (PM, specialty dispersion or nonlinear fibers), environmental packaging, and the inclusion of motorization and control electronics.

How can I find, compare, and request quotes for optical delay lines on FindLight without creating an account?

On FindLight, navigate to Fiber Optics → Optical Networking → Optical Delay Line and use the filters (e.g., delay range, wavelength, fiber type, motorized/manual) to narrow down the listings. You can open product detail pages to compare specifications side by side, then use the built-in RFQ or contact form on each listing to send technical requirements and request quotes directly from suppliers without registration.

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Optical Delay Line

Optical Delay Line Modules for Precise Timing

Optical Delay Lines with Sub-Picosecond Resolution

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Sold by: OZ Optics Ships from: Canada

Specifications
Travel Range:	50 mm
Resolution:	635 um
Delay Range:	167 psec
Delay Resolution:	2 psec
Delay Range (standard):	167 ps

Did You Know?

Did you know that optical delay lines play a crucial role in precision timing across modern photonic systems - from quantum experiments to advanced radar? These components allow engineers to control the timing of light signals by introducing precise delays in the optical path. By adjusting the length or refractive index of the medium through which light travels, delay lines make it possible to synchronize signals with nanosecond or even picosecond accuracy. They are commonly used in applications like optical coherence tomography (OCT), interferometry, and high-speed telecommunications. Variable or tunable delay lines are especially valuable in lab settings, enabling real-time testing and calibration of photonic devices. Whether it’s to match signal arrival times in a quantum optics experiment or to simulate distance in an RF photonics system, optical delay lines offer a flexible and indispensable solution. At FindLight, you’ll find both fixed and tunable optical delay lines in fiber and free-space formats, engineered for performance and precision across a wide range of wavelengths.

Frequently Asked Questions

An optical delay line is a device that introduces a controlled time delay to an optical signal by increasing its optical path length in free-space, fiber, or integrated waveguides. It operates by routing light through an adjustable or fixed additional path, so the group delay of the signal is modified without necessarily changing its wavelength or modulation format.

What Is an Optical Delay Line?

An Optical Delay Line is a device that introduces a controlled time delay to an optical signal, typically by varying the optical path length in fiber or free space. In fiber-based implementations, the delay is determined by the fiber length and refractive index, while tunable designs use coils, translation stages, or optical switches to change the effective path in real time. These components are essential in timing alignment, coherent detection, signal synchronization, and test setups where precise control of group delay is required.

Typical Specifications and Use Cases

When selecting an Optical Delay Line on FindLight, engineers commonly evaluate:

Wavelength range: Often specified for 850 nm, 1310 nm, 1550 nm, or C/L-band operation, with single-mode or multimode fiber options.
Delay range: Fixed or tunable delays from picoseconds to microseconds, corresponding to path lengths from centimeters to many kilometers of fiber.
Insertion loss: Total optical loss through the delay line, typically in dB, affecting link budget and system sensitivity.
Polarization handling: Use of PM fiber, polarization control, or depolarized designs for coherent and interferometric systems.
Dispersion and bandwidth: Chromatic dispersion and group delay ripple that impact short pulses and high-speed modulation formats.
Actuation and tuning: Manual stages, motorized translation, fiber switches, or electronically controlled modules for dynamic delay adjustment.
Connectors and packaging: FC/PC, FC/APC, LC, or SC interfaces, benchtop or rack-mount enclosures, and environmental ratings.

Common applications for an Optical Delay Line include optical coherence tomography (OCT), interferometry, coherent communications testing, MIMO and beamforming experiments, optical time-domain reflectometry (OTDR) calibration, and synchronization of distributed sensing systems.

Buyer Guidance on FindLight

Use this page to compare Optical Delay Line products by wavelength, delay range, insertion loss, and polarization requirements relative to your network or lab setup. Check mechanical interfaces, fiber type, and control interfaces (USB, Ethernet, analog) for integration with your existing instrumentation. For detailed pricing or custom configurations, you can request quotes directly from suppliers through FindLight. No registration is required to contact vendors, enabling rapid evaluation and sourcing of the Optical Delay Line that matches your technical and budget constraints.