VPH (体相全息)衍射光栅

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筱晓光子光学仪器组件, 体相全息Volume Phase Holographic (VPH) 衍射光栅技术的光谱仪相对于传统的刻划光栅，具有低散......

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【技术特点】-- VPH (体相全息)衍射光栅

VPH (体相全息)衍射光栅

体相全息Volume Phase Holographic (VPH) 衍射光栅技术的光谱仪相对于传统的刻划光栅，具有低散射，受偏振影响小的特点，同时牢固耐用，是理想的高端光谱和光通讯仪器。

What are VPH diffraction gratings?

The most commonly used gratings are generally ruled or etched using either a process involving the mechanical scratching of the surface of a substrate, or exposure of a photoresist layer deposited on a substrate.where the interference pattern produced by two coherent light beams is used to expose the photoresist. The diffraction gratings produced with this process are often called holographic. Both of these processes are used to create a fine, periodic relief pattern on the surface of a blank substrate. Such a relief structure can predictably modify the amplitude and/or phase of the incident light. The superposition of the effects of many such grooves allows for the angular separation of the spectral components of the incident light. Depending on whether the light is reflected from the grooved surface, or transmitted through it, the grating is called either a reflection or transmission diffraction grating.

A typical VPH grating manufacture process is illustrated below. A layer of photosensitive gel is enclosed by two substrates. Usage of gel between two substrates gives many more degrees of freedom in the spectral response of these gratings. The width, shape and depth of the fringes all affect the grating performance.

VPH光栅产品目录

透射式凝胶光栅（Gel Grating），又称体相全息衍射光栅（VPH Grating）, 完全不同于传统的表面凹凸性光栅，凹凸性光栅通过光栅表面的沟槽深度的周期性变化，对光的相位进行调制，从而完成分光，而VPH光栅则通过凝胶层的折射率n的周期性变化对入射光进行调制，完成分光。Wasatch Photonics 通过自己的zl及相应的商业保密技术，生产增强型体相全息衍射光栅Enhanced-Volume Phase Holographic Gratings (VPHGs) 及全息光学元件 (HOEs). 高性能的光栅可以适合多种应用场合， Dickson Gratings® 光栅是一种专门设计的特殊VPH光栅，具有高色散能力，在偏振S & P都具有高衍射效率，并具有低偏振损耗特点。这种透射型光栅可以使得分光系统更加小巧、结构简化、减少光学元件的使用，设计灵活，制作简单。

光谱范围：350nm—2400nm

波前畸变：典型值1/4wave,更高精度可定制

波前均匀性：<1/40waveRMS

空间频率：125 lp/mm —-3600lp/mm

Volume Phase Holographic Gratings These are theoretical models of transmission gratings, unless stated otherwise. We have made many of these gratings for customers and measured performance that compares to the theoretical models.. We are happy to make them for you although we do not stock most of these gratings.
黄色的表示为Dickson Gratings®光栅，具有对S& P偏振光具有最大衍射效率，并且低PDL（偏振损耗）
灰色的表示对S和P偏振光的衍射效率非常匹配
绿色表示对S (TE) 偏振光具有最高衍射效率
浅蓝色表示对P (TM) 偏振光具有最高衍射效率
紫红色表示低色散光栅(LD-XXX)
? Diffraction Efficiencies: Best Plots ? Assumptions: 5-8% total loss (reflection, absorption, & scattering)	Spatial Frequency (lpmm)	CWL or blaze wavelength (nm)	Nominal AOI/AOD (degrees)	Notes
3600 lpmm at 415nm Dickson® single pass grating	3600	415	48.3
3000 l/mm at 360 nm	3000	360	32.68
2730 lpmm at 532 nm Dickson® single pass grating	2730	532	46.6
2400 l/mm at 415 nm	2400	415	29.87
2400 lpmm at 532 nm	2400	532	39.67	S polarization >92%
2400 lpmm at 532 nm	2400	532	39.67
2400 lpmm at 590 nm	2400	590	45.07	Highest Average
2300 lpmm at 532 nm	2300	532	37.7	S polarization >92%
2300 l/mm at 520 nm	2300	520	36.73
2300 lpmm at 532 nm	2300	532	37.7
2300 lpmm at 605 nm	2300	605	44.09
1850 lpmm at 785 nm Dickson® single pass grating	1850	785	46.6
1840 lpmm at 800 nm Dickson® single pass grating	1840	800	47.4
1800 l/mm at 532 nm	1800	532	28.6
1800 lpmm at 785 nm	1800	785	44.95	S polarization >92%
1800 lpmm at 800 nm	1800	800	46.05
1800 lpmm at 800 nm Quasi-Dickson® single pass grating	1800	800	46.05
1800 lpmm at 830 nm	1800	830	48.33
1750 lpmm at 830 nm Dickson® single pass grating	1750	830	46.6
1700 lpmm at 830 nm	1700	830	44.87	S polarization >92%
1700 lpmm at 1054 nm	1700	1054	63.6	S polarization >92%
1670 lpmm at 880 nm Dickson® single pass grating	1670	880	47.29
1608 lpmm at 880 nm Quasi-Dickson® single pass grating	1608	880	45.0
1500 lpmm at 800 nm	1500	800	36.87
1500 lpmm at 830 nm	1500	830	38.5
1300 l/mm at 560 nm	1300	560	21.35
1245 lpmm at 1185 nm Dickson® single pass grating	1245	1185	47.53
1200 lpmm at 500 nm	1200	500	17.46
1200 lpmm at 550nm	1200	550	19.3	P Polarization
1200 lpmm at 600nm	1200	600	21.1
1200 lpmm at 785 nm	1200	785	28.1
1200 lpmm at 800 nm	1200	800	28.68
1200 lpmm at 830 nm	1200	830	29.87
1200 lpmm at 850 nm	1200	850	30.66
1200 lpmm at 920 nm	1200	920	33.5
1200 lpmm at 1032 nm	1200	1032	38.3	S Polarization >90%
1156 l/mm at 655 nm	1156	655	22.25
1132 l/mm at 610 nm	1132	610	20.20
1145 lpmm at 1310nm Dickson® single pass grating	1145	1310	48.59
1110 lpmm at 1310nm Dickson® single pass grating	1110	1310	46.6
1095 lpmm at 700nm	1095	700		P Polarization >90%
1026 l/mm at 735 nm	1026	735	22.15
940 lpmm at 600nm	940	600	16.4
940 lpmm at 850 nm	940	850	23.55
940 lpmm at 875 nm	940	875	24.28
940 lpmm at 1550 nm Dickson® double pass reflection grism	940	1550	46.761
940 lpmm at 1545 nm Dickson® double pass grating	940	1545	46.565	6.4 degrees per 40 nm
940 lpmm at 1545 nm Dickson® single pass grating	940	1545	46.565	3.2 degrees per 40 nm
940 lpmm at 1510, 1545, 1590 nm Tunable Dickson® single pass grating	940	C, S, L Bands	varies	~3 degrees per 40 nm
900 lpmm at 1310 nm	900	1310	36.12
850 l/mm at 885 nm	850	885	22.09
800 lpmm at 480 nm	800	480	11.07
600 lpmm at 1310 nm	600	1310	23.14
600 lpmm at 1550 nm transmission	600	1550	27.710
600 lpmm at 560 nm	600	560	9.67
600 lpmm at 600 nm	600	600	10.37
600 lpmm at 633 nm	600	633	10.95
600 lpmm at 800 nm	600	800	13.89
600 lpmm at 900 nm	600	900	15.66
600 lpmm at 1570 nm	600	1570	28.1
540 lpmm at 740 nm	540	740	11.53
425 lpmm at 650 nm	425	450-850
400 lpmm at 650 nm	400	650	7.470
300 lpmm at 1550 nm double pass reflection	300	1550	13.44
250 lpmm at 1700 nm	250	1700	12.27
LD-220 lpmm at 550 nm	220	400-700		>35%
LD-155 lpmm at 1325 nm	155	950-1700		>35%
LD-125 lpmm at 550 nm	125	400-700		>35%
LD-118 lpmm at 550 nm	118	450-850		>35%

Capabilities:
	Custom Groove Frequencies
	Custom Wavelengths
	Prism & Mirror Configurations
	Various Substrates (e.g. Fused Silica)
	AR Coating
	Aluminum & Gold Reflection Coating