POC-OC-122422-PPKTP Crystal

General Description

Periodically Poled Potassium Titanyl Phosphate (PPKTP) is a nonlinear crystal widely used in photonic applications for its exceptional ability to achieve high-efficiency frequency conversion through Quasi-Phase Matching (QPM). This crystal is engineered with a unique structure featuring alternating self-polarized domains that facilitate QPM processes. The key advantage of PPKTP is its capacity to correct non-collinear phase mismatches, enabling robust nonlinear optical interactions across its broad transparency range (350–4000 nm).

Due to its high nonlinear coefficient and broad transparency range, PPKTP is an ideal choice for demanding photonics applications such as second-harmonic generation (SHG), sum-frequency generation (SFG), and spontaneous parametric down-conversion (SPDC). These properties, combined with its robust structural stability, make PPKTP crystals versatile for laser technology, quantum optics, spectroscopy, and biomedical imaging applications

General Applications and Examples

PPKTP crystals have a wide range of applications in photonics, particularly in areas requiring efficient nonlinear optical processes. Some notable applications include:

1. Spontaneous Parametric Down-Conversion (SPDC):
   • PPKTP is a key material for SPDC processes in quantum optics. It enables the generation of entangled photon pairs, a critical resource for quantum key distribution, quantum computing, and quantum imaging.
   • Example: A single PPKTP crystal can be used in a quantum entanglement setup to create pairs of photons with high efficiency and purity.
2. Second-Harmonic Generation (SHG):
   • Widely used for generating visible green laser light from infrared lasers, SHG applications in PPKTP often operate near the 1 μm wavelength range.
   • Example: PPKTP crystals are employed in green laser pointers and compact solid-state lasers used in spectroscopy.
3. Sum-Frequency Generation (SFG):
   • SFG in PPKTP is utilized in various spectroscopic and imaging techniques, including biomedical imaging and chemical sensing.
   • Example: SFG microscopy combines infrared and visible light to provide highly sensitive, label-free imaging of biological samples.
4. Frequency Conversion Applications:
   • PPKTP crystals facilitate frequency doubling and tripling in laser systems, enabling the creation of tunable laser outputs for industrial and scientific uses.
5. Broadband Applications:
   • PPKTP crystals support a wide transparency range, making them suitable for multi-wavelength optical communication and high-precision laser-based instrumentation.