By making use of the unique properties of liquid crystal materials, liquid crystal displays (LCDs) as well as many other liquid crystal photonic devices have been playing an important role in serving our daily life. Many LC devices need to have fast response time as well as good electrooptical properties. Ferroelectric liquid crystal, well known for its fast response time, can be a good candidate for a variety of applications. A new proposed FLC mode called electrically suppressed helix (ESH) FLC is characterized by fast response, high contrast ratio, good mechanical stability with low driving voltage has attract of much attention. In this thesis, the properties for ESH FLC are introduced in detail and polymer stabilized ESH FLC have been proposed to further stabilize the optical prope...[ Read more ]

By making use of the unique properties of liquid crystal materials, liquid crystal displays (LCDs) as well as many other liquid crystal photonic devices have been playing an important role in serving our daily life. Many LC devices need to have fast response time as well as good electrooptical properties. Ferroelectric liquid crystal, well known for its fast response time, can be a good candidate for a variety of applications. A new proposed FLC mode called electrically suppressed helix (ESH) FLC is characterized by fast response, high contrast ratio, good mechanical stability with low driving voltage has attract of much attention. In this thesis, the properties for ESH FLC are introduced in detail and polymer stabilized ESH FLC have been proposed to further stabilize the optical properties to make it suitable for some applications.

By using the ESH FLC, two optical element structures are produced: gratings and fork gratings. For gratings, we have demonstrated the switchable and optical rewritable grating structure based on FLCs with ultra-fast switching speed and high diffraction efficiency at small electric field. The response time of 50^µs at 6.67V/μm has been achieved. Two modes are demonstrated: GRATING/OFF mode and GRATING/TRANSMISSION mode. The proposed grating can be erased, re-written optically for different grating profiles with simple steps. Theoretical calculations have been made for both modes and the FLC cone angle effect on diffraction efficiency is discussed in detail to further explain the advantage of this material. All the experimental results fit the theoretical calculations very well. For fork gratings, we have demonstrated the switchable fork grating structure based on FLCs with ultra-fast switching speed and high diffraction efficiency at small electric field. Two modes are introduced: FORKGRATING/OFF mode and FORKGRATING/TRANSMISSION mode. Furthermore, using DMD system provides us a very easy way to fabricate the fork grating cell with very high alignment quality. We believe this method shows great potential to find application as element for projection display, Pico-projectors and various photonic elements.

Another approch is that we propose a new type of display-field sequential color display based on ESH FLC which shows many advantages. The main obstacle for this kind of display is that it requires fast response time LC to eliminate color breakup. So we proposed the display cell with ultra fast response time and good electro-optical properties. We manage the display quality in many ways to get the best contrast ratio, color gamut, response time and stability. Two different display modes have been introduced. For transmissive mode, we have given the results for many display parameters and shown good quality of our display cell. We also build up our own prototypes including prototypes of manually changing colors, automatically changing colors and the multiple pixels display. For reflective mode, we have obtained some preliminary results which can show its fast response time with very small electric field requirement thus it is very suitable for pico-projector use.

The driving method for our ESH FLC display is very important. We define the general timeline for ESH FLC display. The 8 bit gray level generation in each sub frame has been discussed in detail.